Now we know why Yahoo bought Tumblr for $1.1 billion. Or at least one of the reasons why.

Tumblr is on the verge signing a deal with Ditto Labs, a Massachusetts-based company that scans photos posted on social media websites for brand-related data, according to a recently-published report from tech website Mashable.

In other words, if you post a photo of you standing in front of your car onto a social network, Ditto Labs will use its technology to recognise the exact brand of that car, such as a Cadillac, and then report any mined data to whoever pays them.

Tumblr is the latest company ready to use Ditto Labs' services. Although T.R. Newcomb, the head of business development at Tumblr, told Mashable that Tumblr currently isn't planning anything advert-related, it is interested in helping other companies "understand the nature" of the conversations about their brands on Tumbr.

It sounds like Tumblr wants to tell companies how often their brands are being shown off in photos posted to Tumblr, though it's unclear why Tumblr would do that unless it is interested in advertising one day. Keep in mind many big companies already use Ditto's services, including Cadillac, and now they will have access to even more inclusive reports with this new Ditto Labs-Tumblr deal.

And finally, we're not sure how Tumblr's user base will feel about the deal, especially after Marissa Mayer, the chief executive officer at Yahoo notably promised users last year that the acquisition of Tumblr wouldn't "screw [Tumblr] up".