I'm curious if anyone knows how Pierre's "Cash-back Rewards Program" works. I get that it's a mail-gift like you get from other villagers, but what determines the amount? Does it actually have anything to do with shopping in his store, or is that implication strictly for flavor? All the wiki says about the amount is "250g (or more)", which needless to say isn't very enlightening
I'm not entirely sure. I have noticed that it seems to be completely random though (if you were to wake up and receive the cash back reward, then exit the game and reload it, you'll get a different amount -- it only went as high as 500g, iirc).
I noticed that it changes the amount too. I suspect (based on my own observations) it's a percentage of what you spent at his shop since the last time it was sent out. In the months I've spent more, it's bigger, spent less, it's smaller. Just my guess.
I'm pretty sure I've got as much as 1000, or maybe like 1100 or so even. But if reloading can change it, that does seem to be a strong indicaton that it's just random. Though I suppose something else (e.g. how much you spend, or how much he likes you) could still have an effect on it.
I believe it's probably just random, actually. I've gotten rewards back even in seasons that I've spent /nothing/ at Pierre's. The wiki lists the money as being tied to your friendship level with him-- the game presumes if you've got a high friendship with Pierre, you must be visiting his store often to shop (since he's seldom seen outside the store to talk with). So technically you could just visit him, give him gifts, and never spend a dime in his store, and still get the 'cash back' on money you didn't spend. Maybe Pierre's book-keeping skills aren't the best around.