New loyalty update edges payments specialist towards the 'social mobile local' space.
There are few start-ups making as much impact as Square right now. Its plug-in reader turns any smartphone or tablet into a device that can accept card payments, and it now has 2m users processing $6bn a year.
Little by little, Square is evolving its service into a richer offering beyond pure transactions.
Last year it introduced the Pay With Square app that displays a photo of the users' face on the merchant's app, so the customers can just walk up to the register and say their name to pay.
Now, it's adding a loyalty component with a similar dynamic.
Rewards gives Square customers a digital version of a paper-based punchcard like you'd get in a coffee shop.
It will be introduced as an upgrade to the merchant's Register app to apply give points to regular customers and then apply discounts automatically when they return to the store.
And, of course, the feature aggregates all kinds of analytics so retailers can tweak their offerings for best results.
The move would seem to be part of a staged plan to move Square from a dumb payments processor to an all-round m-commerce specialist.
In this sense, it's edging Square closer to the many mobile loyalty firms out there, and even to Google Wallet and Apple Passbook.
It's a fearsomely competitive landscape, but Square has momentum behind it and - unlike many of its competitors - its own payments channel with millions of merchants signed-up.