It’s easier to sell ads if you can prove they push product. That’s why Google and Facebook have gotten into the e-commerce business, why Amazon has gotten into the advertising business, and it now appears to be why Yahoo is buying a social shopping site.

Yahoo has agreed to acquire Polyvore, which is like a fashion-centric version of Pinterest. People and brands can use Polyvore to post fashion products like articles of clothing or accessories, create outfits from these items and share them with others. And people perusing outfits on Polyvore can click on individual garments and then click to buy them on one of 350 participating retailers’ sites.

Yahoo did not disclose how much it is paying for Polyvore.