The name of the first advertising service for Twitter. Sparq provides a self-service interface that lets advertisers quickly set up the ads. The ads appear on the right-hand column on Twitter as Tweet Now. When someone clicks on the link, it automatically populates the tweet box with the advertiser's message. This can include a link, as well as an option for the user to customize or add to the message.
See "Is Sparq the Future of Twitter?" on InternetNews.com.