This is a strange acquisition for Apple. It tends to focus more on hardware, software, and applications.
Topsy is one of the companies paying for access to Twitter's firehose of data. It analyzes tweets looking for trends.
The Journal doesn't seem to know what Apple is planning for Topsy, but it suggests Apple will use Topsy for improving advertising in iTunes Radio, Apple's streaming radio service.
We're stumped too, we have no idea what Apple is going to do with this one.
Matthew Panzarino at TechCrunch speculates Apple could use it to improve App Store recommendations/rankings.
Apple for its part isn't saying. A spokesperson just says, "Apple buys smaller technology companies from time to time and we generally do not discuss our purpose or plans."
