Just For U is a comical disaster if a flop. It's the sort of user friendliness/usability you expect from the marketing team of an old grocery story -- an A/B -test driven development by finite monkeys at keyboard

With the Safeway app, you don't get exactly the same coupons as your friend, but in my experience they're almost the same set. However, the app does achieve price discrimination without personalisation: people that are money-rich but time-poor won't bother checking the app for coupons before they go to the checkout, so will pay more than someone who pinches pennies.

But this form of price discrimination is not personalised. It's the same as that achieved with coupons published in magazines.