Apple has purchased Topsy, a search engine and analytics firm for tweets that's been one of Twitter's biggest partners, reports The Wall Street Journal. Though there's no clear implication for what Apple might do with Topsy, the Journal suggests that it could begin using Topsy's data to better target ads, to inform users of its products about popular subjects, or to generally tap into of-the-moment interests. Apple confirmed the acquisition to the Journal, which reports that the purchase price was over $200 million.

Topsy recently announced the launch of a search engine for tweets that it said was capable of searching through the over 400 billion sent since Twitter first launched. Twitter itself doesn't provide a way to do that yet, and in the past it even ended up relying on Topsy's data to parse through the most buzzed-about nominees for the 2013 Oscars and to capture the mood of the 2012 presidential election. That close relationship has allowed Topsy to be one of the few companies given access to Twitter's full stream of data.

Though Topsy's focus is on Twitter for now, the Journal reported back in 2009 that Topsy could eventually expand into analyzing other sources of data. Rather than Apple being interested in social data from Twitter, it's possible that it's also interested in applying Topsy's analytics technology to its own data, such as information from the App Store. As is customary, Apple declined to elaborate to the Journal on its exact intentions, only saying that "Apple buys smaller technology companies from time to time, and we generally do not discuss our purpose or plans."