square register

The promise of social checkins has always been that they’ll make money by revealing to marketers where you are and when you want to buy stuff. Payments startup Square thinks it can do ya one better: telling marketers where you already bought stuff and where you’re likely to want to buy more in the future.

In a chat with The Verge, Square discovery chief Ajit Varma said, “We can tell you that people who like X might also like Y, and it’s a true representation of what you’ve bought.”

Making shopping recommendations isn’t exactly cutting-edge anymore. After all, it’s how old-school behemoth Amazon sells you so much crap and how equally old oldster Netflix keeps you glued to your laptop screen watching old episodes of Breaking Bad long after you should have been asleep.

But Square has a very slight advantage: It knows not only what you buy, but exactly, geographically where you buy it. And it knows not what your interests or “likes” are, but what you actually put plastic to magnetic strip reader for.

The big missing piece in Square’s data treasure trove is something online retailers do very well: tracking what you almost bought and what you might want to look at again, and trying to predict when and where you’ll change your mind and push the button on a purchase decision.

Square has made some big pushes toward more rapid growth (which means more user data) lately. It launched a cheap-o, $300 Business-in-a-Box program to help would-be small business owners get off the ground. And it’s selling its credit card-reading dongles everywhere, from Starbucks to Verizon.

Currently, Square is processing around $10 billion in consumer purchases each year.