Twitter is acquiring TellApart, an 80-person retail retargeting company based in Burlingame, Calif.
TellApart works with a number of major retailers, including Neiman Marcus, Pottery Barn and Wayfair, Twitter noted in a blog post announcing the acquisition.
In its marketing materials, TellApart emphasizes its "cross-device" expertise, but advertising effectively across mobile and desktop is difficult given the unreliable nature of cookies on mobile devices. The best cure to this problem is login data, and Twitter has lots of it. In its earnings report today, the company claimed 302 million monthly active users, all of whom log in.
It's worth noting that Twitter has been pushing its "Buy" button recently, new functionality currently open to a select group of Twitter users that allows them to sell things from right within the app. Here's one such offer the NBA's Atlanta Hawks posted last week: