---
title: "Top Banner Traffic: Create, Test & Improve Ad Performance"
canonical: "https://froggyads.com/top-banner-traffic/"
markdown_url: "https://froggyads.com/top-banner-traffic.md"
description: "Evaluate top banner traffic through banner inventory, sizes, viewability, creative testing, source reporting, tracking and accepted campaign economics."
language: "en"
---

Buyer shortlist

# Top Banner Traffic

Evaluate top banner traffic through banner inventory, sizes, viewability, creative testing, source reporting, tracking and accepted campaign economics, with controlled budgets and decision rules that avoid unsupported performance guarantees.

[Create My Free Account](https://premium.froggyads.com/#/signup)[Explore Banner Ads](https://froggyads.com/banner-ads-guide/)Self-serve control ·750+ SSP integrations ·20B+ daily impressions

![top banner traffic planning visual](https://froggyads.com/assets-redesign-2026/images/v80-native-traffic-banner-network/top-banner-traffic-hero.svg)

Direct answer

## What Top Banner Traffic Means

Top Banner Traffic refers to display inventory delivered through visible graphic units in fixed or responsive placements across websites and apps. Buyers combine a banner creative, destination and tracking chain, then evaluate viewability, clicks, source quality and accepted backend outcomes. Comparison words should not be treated as universal rankings. Define required markets, inventory, reporting, creative support, billing and accepted outcomes, then compare candidates under the same test rules.

01 • Format mechanics

## Understand How Banner Ads Are Delivered

Top Banner Traffic begins with the real delivery model. Banner units appear inside visible display placements and invite an intentional click. Delivery can use standard dimensions, responsive containers or app-specific slots, with viewability and placement quality affecting the opportunity to engage. For top banner traffic, document the event chain from auction and impression through interaction, destination load, click identification and accepted backend outcome. Separate problems caused by rendering, placement, creative, destination speed and attribution. A platform total is not enough when the buyer cannot connect spend to a source and a validated result.

02 • Evaluation focus

## Define what Top Banner Traffic means for the campaign

The commercial wording in top banner traffic should be converted into a measurable buyer requirement. In this guide, the useful boundary is a shortlist built from fit, evidence and test economics. Write the required GEOs, devices, inventory type, reporting fields, budget, attribution window and accepted outcome before comparing options. This prevents broad words such as best, top, cheap, trusted, global or fast from becoming unsupported promises. The correct conclusion can differ by offer, destination, creative capacity, compliance needs and the value of an accepted result.

03 • Inventory context

## Evaluate Supply Beyond a Volume Claim

Inventory quality for top banner traffic depends on where and how the ad appears, not only how many impressions are available. Ask which sizes, devices, apps, sites, positions and source IDs are available. Confirm whether viewability, placement category, frequency, whitelists, blacklists and bid adjustments can be reported or controlled. Confirm whether the platform can preserve placement identifiers through reports and tracking parameters. Review the likely mix by GEO, browser, operating system, connection type and time of day. A broad reach claim is useful only when the buyer can isolate segments, control exposure and compare accepted outcomes under a consistent attribution model.

04 • Audience fit

## Define Eligibility Before Buying Reach

For Top Banner Traffic, the Define Eligibility Before Buying Reach checkpoint should answer a concrete buyer question rather than repeat a generic framework. Compare List, offer, devices, languages, supported and action under the same scope and review window; if one is unknown, keep that uncertainty explicit rather than filling the gap with an estimate. Set a written pass condition and a rollback condition before acting, so the team can reverse the change without rewriting the history of the test. For a FroggyAds campaign, translate this conclusion into the narrowest applicable targeting or budget change and reconcile the result with the accepted business event.

**Connect the guide to live testing**

## Connect Top Banner Traffic to a controlled audience test

For the Top Banner Traffic decision, use Connect Top Banner Traffic to a controlled audience test to separate a real operating requirement from a broad best-practice statement. Keep the review anchored to choices, established, Define, Eligibility, Buying and Reach; those details are the parts of this section that can materially change the recommendation. When the evidence is strong, carry the exact setting or requirement into the next campaign step instead of broadening several variables at once. If the next step is a media test, FroggyAds lets the advertiser keep campaign settings and source-level performance visible instead of treating traffic volume as proof of success.

[Create My Free Account](https://premium.froggyads.com/#/signup)

![Illustration of audience targeting controls for a top banner traffic test](https://froggyads.com/assets-redesign-2026/images/showcase-audience-targeting.svg)

05 • Creative system

## Build Creative Assets for the Real Placement

Test a clear hierarchy with one primary message, readable brand identity and a strong but accurate call to action. Design for the actual placement size rather than shrinking a desktop concept into every unit. For top banner traffic, create several distinct concepts instead of minor color changes. Each concept should express one benefit, problem, proof point or use case and should be traceable through a unique creative identifier. Record the source files, launch date, message angle and destination version. This makes creative fatigue, placement mismatch and source quality easier to distinguish. Never use fabricated ratings, false urgency, fake interface elements or unsupported performance statements.

06 • Responsive production

## Protect Readability Across Devices and Placements

Prepare a focused set of standard and responsive creative sizes, preserve safe zones around text and logos, and verify readability at the smallest delivered dimensions on real devices. Preview top banner traffic in representative desktop, tablet and mobile environments, including slower connections and common browser chrome. Check image crops, headline wrapping, contrast, brand visibility and the area available for the call to action. A creative that looks polished in a design tool can fail when the publisher template crops the focal point or the smallest placement makes the text unreadable. Keep the asset set manageable so each variation receives enough data to evaluate.

07 • Destination continuity

## Landing-page continuity for Top Banner Traffic

The destination should immediately confirm the message shown by top banner traffic. Use a fast, responsive page that identifies the advertiser, explains the real benefit, shows important conditions and provides one clear next step. If the campaign uses an educational article or prelander, it should add truthful context rather than conceal the final offer. Measure response time, engaged sessions, form starts, accepted outcomes and rejection reasons by creative and source. Strong media can appear weak when message continuity or mobile usability breaks after the click.

08 • Attribution

## Create a Reliable Impression-to-Outcome Chain

Pass unique campaign, creative, click, source and placement identifiers wherever the platform supports them. Return validated outcomes through a server-to-server postback or another reliable integration, and align time zones, attribution windows and duplicate rules across the ad platform, tracker, analytics and backend. Before meaningful spend on top banner traffic, complete a live test and confirm the exact identifier stored in every system. The goal is not perfect agreement between tools. It is enough consistent evidence to repeat a source decision and explain material discrepancies.

![top banner traffic controlled workflow visual](https://froggyads.com/assets-redesign-2026/images/v80-native-traffic-banner-network/top-banner-traffic-workflow.svg)

**Choose the execution format**

## Choose a paid-media format that supports Top Banner Traffic

Use the criteria around “Create a Reliable Impression-to-Outcome Chain” to decide whether push, native, display or pop fits the message and destination. Set format, targeting and spend as campaign controls in FroggyAds while the top banner traffic decision remains the standard for judging the result.

[Create My Free Account](https://premium.froggyads.com/#/signup)

![Illustration comparing advertising formats for top banner traffic execution](https://froggyads.com/assets-redesign-2026/images/showcase-ad-formats.svg)

09 • Pricing

## Translate Media Cost Into Accepted Acquisition Economics

Top Banner Traffic may be bought through CPM, CPC, SmartCPC or another supported auction model depending on the platform and inventory. Convert spend into effective CPC, landing cost, accepted CPA, revenue per click and contribution after variable costs. A low headline rate can be expensive when viewability, engagement or backend acceptance is weak. A higher rate can be efficient when the source produces valuable outcomes. Calculate a maximum bid from conservative assumptions and recheck it when conversion rate, approval rate, payout or source mix changes.

10 • Test protection

## Budget, frequency and stop-rule decisions for Top Banner Traffic

For Top Banner Traffic, the Budget, frequency and stop-rule decisions for Top Banner Traffic checkpoint should answer a concrete buyer question rather than repeat a generic framework. Preserve the source, date and owner for controlled, needs, total, loss, limit and daily whenever they affect the decision, especially when the page compares options or sets a budget boundary. If the evidence does not support the current assumption, narrow the scope or run the smallest reversible test that can resolve it.

11 • Traffic quality

## Check Quality Through Behavior and Backend Acceptance

Traffic quality for top banner traffic should be examined through patterns rather than one label. Review device consistency, duplicate identifiers, abnormal click timing, destination engagement, conversion latency, backend rejection reasons, repeat value and the relationship between front-end events and accepted outcomes. Traffic-quality controls can reduce risk but cannot eliminate every invalid event. Compare sources after enough data and time periods mature. A lower-volume source may be more valuable when acceptance and downstream value are stronger.

12 • Source optimization

## Separate Placement, Bid and Creative Decisions

Optimize top banner traffic in layers. First fix tracking, rendering or destination failures that affect every source. Next compare sources and placements under a stable creative and bid. Then test bid changes inside comparable inventory, and test creative or destination changes with controlled allocation. Use whitelists only after a source has enough evidence, and keep a discovery path for new inventory. Avoid reacting to one hour, one conversion or a blended average that hides important source differences.

13 • Creative learning

## Structured creative testing for Top Banner Traffic

Build a creative matrix for top banner traffic that separates message angle, visual concept, headline, call to action and destination. Test a few meaningful combinations, not dozens of nearly identical files. Review served impressions, measurable and viewable impressions when available, clicks, click-through rate, destination engagement, accepted conversion rate, accepted CPA and downstream value by source. Pause clear losers after the planned evidence threshold, but protect promising variations from premature decisions when conversion lag is long. Record why each change was made and what result would support the hypothesis. A disciplined archive becomes a reusable learning system for future GEOs and offers.

14 • Policy and user experience

## Clear, truthful experience requirements for Top Banner Traffic

Banner advertising should remain clearly promotional, load without shifting the page, respect publisher layout and avoid deceptive system-style graphics, forced interaction or claims that the destination cannot support. Review the full path for top banner traffic, including the publisher placement, creative, redirects, landing page, forms, checkout and confirmation. Approval depends on policy, destination behavior, vertical, GEO and campaign details. A clean submission can reduce avoidable delay, but no responsible network should promise that every campaign will be accepted immediately. Keep material terms visible and make it easy for the user to leave or decline.

**Put the guide into practice**

## Turn Top Banner Traffic into a bounded campaign test

For Top Banner Traffic, the Turn Top Banner Traffic into a bounded campaign test checkpoint should answer a concrete buyer question rather than repeat a generic framework. Use Clear, truthful, experience, requirements, documented and launch as the traceable inputs for this section, then state which missing item would be serious enough to stop or narrow the decision. Connect the finding to one owner and one next action so the page helps the visitor decide rather than merely describing a process. A controlled FroggyAds test can turn this section into measurable evidence: keep the conversion definition stable, preserve source identifiers and compare marginal performance before expanding.

[Create My Free Account](https://premium.froggyads.com/#/signup)

![Illustration of a campaign launch checklist for top banner traffic](https://froggyads.com/assets-redesign-2026/images/showcase-campaign-launch-checklist.svg)

15 • Measurement

## Decision scorecard for Top Banner Traffic: media cost to accepted value

On this Top Banner Traffic page, Decision scorecard for Top Banner Traffic: media cost to accepted value matters because it changes what the advertiser should verify before committing budget or operating effort. Keep the review anchored to Review, fixed, schedule, scorecard, covering and delivery; those details are the parts of this section that can materially change the recommendation. Use the finding to choose a specific action—keep, cap, exclude, renegotiate, retest or stop—rather than recording a score with no operational consequence. Where this leads to paid acquisition, FroggyAds gives you a self-serve campaign environment for applying the relevant targeting, budget and source controls while your own analytics verifies downstream value.

![top banner traffic decision scorecard visual](https://froggyads.com/assets-redesign-2026/images/v80-native-traffic-banner-network/top-banner-traffic-scorecard.svg)

16 • Scaling and rollback

## Controlled scaling for Top Banner Traffic after a verified change

Scale top banner traffic only after attribution is stable, accepted acquisition cost is inside the planned range and performance survives a measured increase. Expand one dimension at a time, such as budget, bid, source set, GEO or creative coverage. Monitor marginal performance rather than assuming the historical average will continue. If the source mix, acceptance rate or contribution changes materially, roll back to the last stable configuration and reopen discovery. Results depend on offer, market, creative, destination, competition and optimization, so no page can guarantee the outcome.

17 • Scenario planning

## Conservative, expected and stress scenarios for Top Banner Traffic

Create three planning cases for top banner traffic. The conservative case should use a lower click or engagement rate, weaker backend acceptance and the upper end of expected media cost. The expected case should use evidence from the first controlled cohort, not a sales estimate. The stress case should model a sudden shift in source mix, creative fatigue or a longer conversion delay. Calculate the spend, accepted outcomes and contribution for each case. Scenario planning does not predict the future, but it shows how much performance can deteriorate before the campaign crosses its loss limit and which signal should trigger a rollback. Keep the interpretation anchored to Conservative, expected and stress scenarios for Top Banner Traffic: the buyer still needs to compare a shortlist of options and the attributes that matter. The adjacent Global Banner Traffic page covers a different decision.

18 • Operator checklist

## Close the Top Banner Traffic review with a dated action and evidence requirement

A buyer evaluating Top Banner Traffic can use Close the Top Banner Traffic review with a dated action and evidence requirement to make the page actionable: identify the condition, document the evidence, and define the response. Translate the section into checks for review, record, creative, active, bids and caps; this keeps the recommendation tied to the page's real task instead of generic marketing language. Use the finding to choose a specific action—keep, cap, exclude, renegotiate, retest or stop—rather than recording a score with no operational consequence. FroggyAds is useful here because the media-buying decision can stay separate from the broader strategy decision: launch a bounded campaign, inspect source performance and scale only verified value.

Decision controls

## Practical Review Table for Top Banner Traffic

| Area | Evidence required | Action |
|---|---|---|
| Creative fit | The asset is legible and truthful in the real placement | Keep only distinct concepts with stable delivery |
| Attribution | Creative, click and source IDs reach the backend | Run a live accepted-outcome test |
| Quality | Engagement, acceptance and rejection reasons are visible | Pause abnormal or low-value sources |
| Economics | Effective CPC and accepted CPA are calculated | Compare against the planned limit |
| Scaling | Marginal performance remains stable | Increase one dimension in measured steps |

Questions media buyers ask

## Top Banner Traffic FAQ

### calm audit: should Top Banner Traffic prove the business signal?

calm audit: Top Banner Traffic defines the business signal. consistent check: Top Banner Traffic caps the stated investment cap. reliable budget check: Top Banner Traffic checks record agreement.

### clear validation: who owns the Top Banner Traffic buying plan?

clear validation: Top Banner Traffic assigns the account owner. steady review: Top Banner Traffic records the buying plan. consistent audit: Top Banner Traffic states the important limitation.

### How can a Top Banner Traffic test isolate the effect of one offer?

Keep the audience, placement, destination, creative format, and measurement window fixed while the offer changes. Use the original campaign cell as the reference, compare qualified commercial outcomes, and investigate delivery differences before declaring one offer stronger.

### cautious briefing: does Top Banner Traffic cite a traceable reference?

cautious briefing: Top Banner Traffic cites the traceable reference. formal sign-off: Top Banner Traffic states the measurement caveat. open check: Top Banner Traffic asks the named reviewer.

### independent approval: should Top Banner Traffic fit the decision-maker group?

independent approval: Top Banner Traffic defines the decision-maker group. plain quality check: Top Banner Traffic checks the decision timing. formal inspection: Top Banner Traffic protects audience relevance.

### gradual reconciliation: should Top Banner Traffic count the review cost?

gradual reconciliation: Top Banner Traffic counts the review cost. practical approval: Top Banner Traffic adds the minimum spend. plain verification: Top Banner Traffic caps the approved test budget. measurable check: Top Banner Traffic checks the qualified action.

### defensible measurement: should Top Banner Traffic trust the quality log?

defensible measurement: Top Banner Traffic reads the quality log. sensible audit: Top Banner Traffic checks the analytics record. practical outcome check: Top Banner Traffic trusts the verified response.

### selective verification: should Top Banner Traffic pause for quality collapse?

selective verification: Top Banner Traffic pauses for quality collapse. reliable debrief: Top Banner Traffic records the important limitation. sensible comparison: Top Banner Traffic verifies the documented correction.

### calm quality check: should Top Banner Traffic improve from reconciled records?

calm quality check: Top Banner Traffic uses reconciled records. consistent pilot: Top Banner Traffic tests a single buying choice. reliable test: Top Banner Traffic keeps the stable comparison segment. local test: Top Banner Traffic checks evidence strength.

### clear release check: can Top Banner Traffic take a small budget increment?

consistent outcome check: Top Banner Traffic takes a reviewed scale step. responsible outcome check: Top Banner Traffic checks the business signal. regular audit: Top Banner Traffic caps the bounded allowance. defensible examination: Top Banner Traffic protects delivery quality.

Related campaign resources

## Continue the Banner Ads Campaign Workflow

[**Banner Ads Guide**Review banner ads mechanics, creative requirements and source controls.](https://froggyads.com/banner-ads-guide/)[**Campaign Reporting**Align click IDs, attribution windows and backend validation.](https://froggyads.com/campaign-reporting-guide/)[**Source Targeting**Preserve placement identifiers for bidding, whitelists and exclusions.](https://froggyads.com/source-targeting/)[**Creative Testing Framework**Turn message hypotheses into controlled, original tests.](https://froggyads.com/creative-testing/)
Build a measurable shortlist

## Build a Controlled Top Banner Traffic Test

For the Top Banner Traffic decision, use Build a Controlled Top Banner Traffic Test to separate a real operating requirement from a broad best-practice statement. Preserve the source, date and owner for Treat, measured, acquisition, define, accepted and verify whenever they affect the decision, especially when the page compares options or sets a budget boundary. If the section exposes a measurement gap, repair that gap before changing the offer, creative and targeting simultaneously.

[Create My Free Account](https://premium.froggyads.com/#/signup)[Visit Learning Center](https://froggyads.com/learning-center/)
Advertiser decision framework

## Top Banner Traffic: what should the advertiser decide next?

For Top Banner Traffic, banner means a visual display placement served in a defined slot. The buying decision is whether that delivery context fits the offer, creative and destination well enough to produce an accepted post-click result. Use What Top Banner Traffic Means and Understand How Banner Ads Are Delivered as the page-specific checkpoints, then judge top banner traffic on creative size, viewability context and landing-page message match plus downstream conversion quality.

For the Top Banner Traffic decision, use Top Banner Traffic: what should the advertiser decide next? to separate a real operating requirement from a broad best-practice statement. Document remain, tied, existing, around, Means and Understand in the same decision record so a later reviewer can see why the option passed, failed or needs a narrower retest. Do not scale the conclusion beyond the evidence window; repeat the check after the next meaningful change in volume, scope or audience. For a FroggyAds campaign, translate this conclusion into the narrowest applicable targeting or budget change and reconcile the result with the accepted business event.

| Decision | What to verify | FroggyAds action |
|---|---|---|
| Top Banner Traffic objective | Use What Top Banner Traffic Means to define the accepted business event and the maximum learning loss for top banner traffic. | Launch one FroggyAds campaign objective for Top Banner Traffic and keep the conversion definition stable. |
| Top Banner Traffic audience | Use Understand How Banner Ads Are Delivered to verify market, device, language and offer eligibility for top banner traffic. | Apply only the FroggyAds targeting controls that change the real Top Banner Traffic customer journey. |
| Top Banner Traffic source evidence | Use Define what Top Banner Traffic means for the campaign to keep source-level differences visible instead of relying on one blended top banner traffic average. | Keep, cap, exclude or retest Top Banner Traffic inventory from documented source evidence. |
| Top Banner Traffic economics | Use Evaluate Supply Beyond a Volume Claim to connect media spend with accepted conversions and downstream value for top banner traffic. | Protect the Top Banner Traffic test with a written budget boundary and a consistent attribution window. |
| Top Banner Traffic scale rule | Use Define Eligibility Before Buying Reach to define the exact evidence that earns the next budget increase for top banner traffic. | Scale Top Banner Traffic one major control at a time and compare marginal performance with the prior baseline. |

### A page-specific FroggyAds test sequence for Top Banner Traffic

1. **Top Banner Traffic outcome:** define the accepted event for top banner traffic and the maximum loss permitted while the first test is learning.

2. **Top Banner Traffic path:** verify market eligibility, device experience, landing-page continuity and tracking against What Top Banner Traffic Means before buying more traffic.

3. **Top Banner Traffic hypothesis:** launch one bounded FroggyAds test tied to Understand How Banner Ads Are Delivered; do not change bid, creative, audience and destination together.

4. **Top Banner Traffic source review:** compare qualified activity, accepted conversions, timing and cost by the source or segment dimensions relevant to Define what Top Banner Traffic means for the campaign.

5. **Top Banner Traffic scaling:** use Evaluate Supply Beyond a Volume Claim and Define Eligibility Before Buying Reach to define what must reproduce before the next budget increase.

### Why FroggyAds is relevant to Top Banner Traffic

Treat Why FroggyAds is relevant to Top Banner Traffic as a specific gate for Top Banner Traffic, not as a reusable checklist item that means the same thing on every page. Review gives, self-serve, ad-network, workflow, buying and supported together, because a strong result in one of them should not conceal a material failure in another. Set a written pass condition and a rollback condition before acting, so the team can reverse the change without rewriting the history of the test.

Make Why FroggyAds is relevant to Top Banner Traffic specific to Top Banner Traffic by tying it to the exact workflow, audience or commercial constraint described on this page. Translate the section into checks for Define, Eligibility, Buying, Reach, final and checkpoint; this keeps the recommendation tied to the page's real task instead of generic marketing language. Do not scale the conclusion beyond the evidence window; repeat the check after the next meaningful change in volume, scope or audience. When the page's recommendation becomes a traffic test, FroggyAds provides the campaign controls to execute it while the advertiser retains responsibility for offer fit, tracking and backend acceptance.

[Create your free FroggyAds account](https://premium.froggyads.com/#/signup)

Search intent and buyer decision

## How to use this Top Banner Traffic page

This URL has one primary job for **performance-focused advertisers**: **compare a shortlist of options and the attributes that matter**. Keep this page focused on that buying decision instead of turning it into a generic advertising article. The nearest related FroggyAds page is [Global Banner Traffic](https://froggyads.com/global-banner-traffic/); use that URL when its narrower task is the one you actually need. On Top Banner Traffic, use this step to compare a shortlist of options and the attributes that matter; record the resulting evidence against this page rather than a neighboring topic.

The unresolved entity checks for Top Banner Traffic are practical operating controls, not extra keywords: verify placement eligibility before judging whether display delivery is weak or simply unavailable. Apply them only where they help you compare a shortlist of options and the attributes that matter.

| Step | Ad Format workflow | Evidence to retain |
|---|---|---|
| 1 | Match the format to the user journey and creative requirement | Keep the evidence tied to Top Banner Traffic and the accepted outcome defined for this URL. |
| 2 | Control targeting, frequency or placement variables that can change the result | Keep the evidence tied to Top Banner Traffic and the accepted outcome defined for this URL. |
| 3 | Compare accepted outcomes by source before scaling the format | Keep the evidence tied to Top Banner Traffic and the accepted outcome defined for this URL. |

### Transparent Top Banner Traffic decision example

**Hypothetical example:** if a controlled Top Banner Traffic test spends USD 250 and records 9 accepted outcomes after the same review window, accepted CPA is USD 250 divided by 9 = **USD 27.78**. Replace the example inputs with your own economics; this is not a FroggyAds performance claim.

Use FroggyAds as the execution layer only when the page's decision calls for paid traffic. Set the relevant budget, targeting and format controls, verify conversion tracking, keep source-level evidence, and increase spend only when the accepted outcome supports the next step. [Create your free FroggyAds account](https://premium.froggyads.com/#/signup). On Top Banner Traffic, use this step to compare a shortlist of options and the attributes that matter; record the resulting evidence against this page rather than a neighboring topic.

**Research basis for Top Banner Traffic:** This URL helps performance-focused advertisers compare a shortlist of options and the attributes that matter. It is mapped to the display research cluster. Our current review used [support.google.com](https://support.google.com/google-ads/answer/9823397?hl=en) and [support.google.com](https://support.google.com/displayvideo/answer/6101342?hl=en) to check terminology, buyer questions and decision coverage relevant to Top Banner Traffic. These external sources are research inputs, not evidence of FroggyAds campaign performance.

Direct answer

## Top Banner Traffic — what matters first

Make Top Banner Traffic: what matters first specific to Top Banner Traffic by tying it to the exact workflow, audience or commercial constraint described on this page. Review format, fits, journey, device, context and creative together, because a strong result in one of them should not conceal a material failure in another. If the evidence does not support the current assumption, narrow the scope or run the smallest reversible test that can resolve it. A controlled FroggyAds test can turn this section into measurable evidence: keep the conversion definition stable, preserve source identifiers and compare marginal performance before expanding.
