Twitter has officially launched their answer to Google AdWords: "Promoted Tweets." The platform will allow advertisers to place their tweets at the top of keyword search results, and future plans include full integration with third party apps and direct placement in user Twitter streams. If a particular "Promoted Tweet" is not "resonating" (AKA replies, clicks, and other metrics), Twitter will pull the ad without cost to the advertiser. Check out the full details at TechCrunch.