According to the Wall Street Journal, one of the new advert styles will take the form of "Twitter cards" and will allow mobile users to download apps with a single click. By clicking a dedicated download button, users will be taken directly to either the App Store or Google Play, making it quicker and easier for them to download new things. The same feature has been included on Facebook for a while, and has seen a huge increase in downloads. No wonder it has proven popular with advertisers then.
Also on the cards is a tool that will allow users to enter competitions with a single click, negating the need for form filling. Which seems a bit like reinventing the wheel, since the concept of "Retweet for a chance to win" has been in play for many years.