Twitter (TWTR) had multiple mobile ad announcements on Monday, including its acquisition of  TapCommerce, a New York advertising technology firm. The social media company is also introducing ads for mobile app installations.

Although Twitter has not yet revealed the price, Re/Code reports that TapCommerce is being purchased for about $100 million. The company uses a “retargeting” strategy to try to get users to look at apps they have previously downloaded.

“Advertisers spend aggressively to get new users, but re-activating existing or previous users can provide just as attractive a return on investment,” Richard Alfonsi, VP of Twitter Global Online Sales, said in a blog post. “TapCommerce enables real-time programmatic mobile ad buying across multiple exchanges reaching over 50,000 apps.”

TapCommerce has raised $12 million in funding from RRE Ventures, Metamorphic Ventures, Bain Capital Ventures, Eniac Ventures and Nextview ventures. Its most recent round was in November.

Earlier on Monday, Twitter unveiled its new plans for mobile app installs, similar to a service that has proven successful for Facebook (FB). Users will see app installation suggestions in their news stream.

Twitter had been beta testing this service and reportedly had strong results. This could be a significant new way for Twitter to generate revenue.

“If executed well at scale, these ads will be very valuable to both the publisher and developer communities,” Harry Kargman, founder & CEO of mobile tech company Kargo, said. “Facebook has already been able to take financial advantage of similar products, and the key for Twitter will be to match Facebook's ability to leverage its huge library of audience data for targeting purposes.”

Twitter, which went public in November, has seen a bit of volatility in its share price. Shares are down 36% year-to-date and closed Monday at $41.

Follow Katie Roof on Twitter @Katie_Roof