Twitter users won't see more ads or any change to their experience other than ads that are more narrowly targeted to the conversations they've held and comments they've made on the experience. And this isn't out of left field—the company has been including what users are talking about into what it calls its "interest graph," so companies could target Tweets based on interests. Wednesday's announcement is about getting more granular.
The example the company gives is someone who Tweets about liking the new album from a favorite band. The venue hosting that band for an upcoming performance could target that Twitter user— with a link to buy tickets—based on their location and their conversations about the album.
(Read More: Twitter Gets Into the Music Biz With New App: Report)
Twitter said it's working, based on early tests. Because the Tweets were more carefully targeted, it said Everything Everywhere (@EE), Microsoft Japan (@SurfaceJP), and Walgreens (@Walgreens), found "users were significantly more likely to engage with Promoted Tweets using keyword targeting in timeline than other forms of targeting in the timeline."
This could be a key move in helping drive Twitter's ad revenue higher. The company said that @GoPro, which sells wearable and gear-mountable cameras, saw engagement rates as high as 11 percent.
With that kind of response rate, compared to a click through rate of just a tenth of a percent for U.S. display ads, according to DoubleClick, Twitter may quickly draw more ad dollars.
(Read More: Things You Didn't Know About Twitter)
—By CNBC's Julia Boorstin; Follow her on Twitter: @JBoorstin