In this video, Motley Fool tech and telecom analyst Andrew Tonner tells investors about a recent study from a group of economists at eBay's (NASDAQ:EBAY) Research Labs, comparing geographic areas where the company had withdrawn its Google (NASDAQ:GOOGL) ads with areas where it hadn't over a three-month period. The company found no significant loss in sales between the two areas. Does this call into question the efficacy of advertising with Google? Andrew tells us why having a major advertiser like eBay lose faith might have an impact on Google, and he gives investors some key takeaways for their own investing theses on these two companies.

Andrew Tonner owns shares of eBay. The Motley Fool recommends and owns shares of eBay and Google. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.