Yahoo! Research partnered with a nationwide retailer to study the effects of online display advertising on both online and in-store purchases. We use a randomized field experiment on 3 million Yahoo! users who are also past customers of the retailer. We find statistically significant evidence...

Advertisers seek to maximize profits by investing in advertising. We propose a “cost-per-incremental-action” (CPIA) pricing model which incorporates the causal contribution of advertising in order to achieve the advertisers' objectives such as profit maximization. CPIA pricing aligns...

We find display advertising influences customer search for both the advertised brand and its competitors. We exploit a natural experiment that randomizes ad delivery on 500 million visits to the Yahoo! homepage and compare visitors' subsequent activities on Yahoo! Search. In three advertisers'...

We measure the causal effects of online advertising on sales, using a randomized experiment performed in cooperation between Yahoo! and a major retailer. After identifying over one million customers matched in the databases of the retailer and Yahoo!, we randomly assign them to treatment and...