T
"We thought you may be running low on toilet paper, so we sent some for free. If you're not, then just tick no and we'll take it back, or [from a comment that was deleted shortly after it was posted] pass it to an Amazon neighbor for a $2 credit."
T+1
"We've noticed you appreciate our pre-emptive notifications, and hope we've been helping you out. We'd like to opt you in to our pre-emptive ordering system, so we can help you forget those small essentials. We've included some complementary, ripe, seedless avocados less than 1 day from the tree they were picked from as a sample of the power this feature can offer; this freshness can't be bought in shops."
T+2
"We've opted you in to our pre-emptive ordering system, where we will send you those daily essentials and special seasonal must-haves. There is no commitment. If we ever send you some thing you don't feel you need, we'll happily take it back at no charge and no effort from you."
The first option there is the same scam that record clubs used. In the UK, at least, any goods sent to you speculatively are yours to keep for free; any attempt to collect payment is illegal.
T+1 "We've noticed you appreciate our pre-emptive notifications, and hope we've been helping you out. We'd like to opt you in to our pre-emptive ordering system, so we can help you forget those small essentials. We've included some complementary, ripe, seedless avocados less than 1 day from the tree they were picked from as a sample of the power this feature can offer; this freshness can't be bought in shops."
T+2 "We've opted you in to our pre-emptive ordering system, where we will send you those daily essentials and special seasonal must-haves. There is no commitment. If we ever send you some thing you don't feel you need, we'll happily take it back at no charge and no effort from you."
There is definitely a business model there.