Audience Insights tool from twitter is to help advertisers gain a better understanding of key audiences, and it should help with their targeting.

With audience insights, you can easily discover valuable insights about your followers and the people who have engaged with your organic Tweets. You can also identify new, relevant audiences to target for an upcoming campaign. Your audience insights dashboard provides aggregate information about user demographics, interests, purchasing behavior and more. Twitter Announces Audience Insights Tool For Advertisersl [blog.twitter.com]

Audience insights is now available to all Twitter advertisers and analytics users. Twitter-specific information can be accessed within the U.S., with plans to roll this out more broadly over the next few months.