But the issue of effectiveness nags here, too. Although most advertisers have come to believe that ads introduced when a customer is shopping true terms are more valuable than the static banner ads that after dominated the web, recent research has cast doubt on that. A 2015 study found that when eBay began and then stopped advertisements on a huge search engine, the agency saw no change in traffic. “That paper introduced into query no matter if these sorts of ads do the rest or not,” says Michael Luca, an assistant professor at Harvard Business School.
A subsequent study found that some advertisers are lowering their spending on search ads. The experiences piqued Luca’s curiosity. Since graduate school he’s been drawn to how data, ratings, and comments have an impact on consumer conduct. Over the past five years he has published papers on the dynamics of school ratings and book comments. He’s also performed a number of reports of Yelp, adding a widely publicized paper concluding that 16% of the restaurant reviews he examined were fake.
As Luca’s analysis began acting, Yelp reached out to talk about how it might probably work with lecturers on a number of research questions. As a result of these conversations, in the course of the summer of 2015 Luca and his colleague Daisy Dai now a professor at Lehigh University moved into cubicles at Yelp headquarters.