Online advertisers have been excited about Pinterest's potential for some time, but today they finally got their wish. Ads are coming to Pinterest. In a blog post, Pinterest laid out its plans for a new system of "Promoted Pins," which would allow corporate partners to promote certain posts within category streams and search results. So far, the model is still in a test mode and, as the post put it, "nobody’s paying for anything yet."

The plan is similar to revenue models already adopted by Twitter and, to a lesser extent, Tumblr. Using data from a user's profile, the ad system can target users interested in a certain product, and promote pins within their stream to make sure they see it. CEO Ben Silbermann said he was determined to keep banner ads off the platform, adding, "we’ll always let you know if someone paid for what you see, or where you see it."