Two Science Inc. portfolio companies came together today, as FameBit, an online marketplace where advertisers buy endorsements from popular YouTube video creators, acquired social media marketing agency Refame.

Refame, which puts together commercial endorsement deals for popular Snapchat, Vine and Instagram stars, will move its business onto FameBit’s online marketplace. The terms of the acquisition were not disclosed.

Both companies were part of Science’s startup studio in Santa Monica, and the slightly larger FameBit will continue to operate there with a combined staff of about 20.

Science Partner Dave Fink would not say if his company’s equity stake in FameBit grew or shrunk. FameBit paid for Refame using its own cash, he said, and the deal was not financed by Science.

By bringing social media stars together on one online marketplace, Science sees FameBit as a more effective way for advertisers to get their message out over the Internet.

“It is really important to be cross-platform,” Fink said. To advertise effectively on different social media apps, “often times it’s the same story and the same consumers, but you have to tell the story differently to engage that customer at that moment.”

Technology reporter Garrett Reim can be reached at [email protected]. Follow him on Twitter @garrettreim for the latest in L.A. tech news.