There is a moment when all social networks tries to make money. Now it seems that
Pinterest has reached this point and it has just introduced advertising through promoted pins.
Promoted pins will be available for US clients but it is expected that these ads will be introduced in the rest of markets pretty soon.
Promoted pins works in a very similar way than Facebook's sponsored posts. The advertiser can pay in order to have his pins displayed to those users who have performed a search with a word related with the products or industry where the advertiser operates.
Pinterest seems to be quite clever and promoted pins can be easily confused with other pins, encouraging people to click on them without noticing that these are advertising pins. Pinterest argues that with this system, the social network will keep its minimalist look. For now it is still being tested and shown to a small number of users but the company will soon start to charge for advertising.
It seems that Google is the company that prefers to keep advertising out of its social network.