Tuesday's acquisition of OnTheAir follows Yahoo's recent purchase of a mobile startup called Stamped. In both cases, Yahoo was drawn more by the engineering talent working at the startups than the services that they have been offering.
Yahoo Inc., which is based in Sunnyvale, Calif., didn't disclose how much it paid for OnTheAir, which is based in San Francisco.
The service enables users to hold online video chats in a talk-show format. Yahoo didn't say whether it intends to continue OnTheAir's service.
Yahoo is in the process of closing Stamped's service just six weeks after announcing that acquisition so the engineers picked up in that deal can focus on other projects. Five of the 11 Stamped employees used to work for Google Inc., where Mayer was a top executive before Yahoo lured her away to become its CEO in mid-July.
One of OnTheAir's employees, Daniel Hopkins, also used to work at Google. The resumes of the four other OnTheAir workers being scooped up by Yahoo list stints at Apple Inc. and instant messaging service Meebo.
"Hiring the most talented mobile product thinkers and engineers is a big priority for us moving forward," Adam Cahan, Yahoo's senior vice president of emerging products and technology, said in a statement.
Mayer has said she believes half of Yahoo's engineering talent must eventually consist of mobile computing specialists.
Yahoo's stock gained 38 cents, or 2 percent, to close Tuesday at $18.93.