Twitter has expanded its advertising options available to advertisers. According to Twitter, the company has added the ability for advertisers to target users based upon keywords used in a user's recent tweets. Twitter says that this is "an important new capability -- especially for those advertisers looking for signals of intent -- because it lets marketers reach users at the right moment, in the right context."
This new feature is similar to Google's advertising offers in that they can reach users that are using certain words. Google offers the ability for advertisers to have ads shown when keywords are used in a search query.
An interesting application of this new option would be a local concert venue geotargeting tweeters who post about an upcoming band. Twitter notes that users shouldn't see much of a difference on their side. The only change will be the promoted tweets will be more targeted.