I use it pretty regularly in the US for a few specific things. The bagel store and the Jamaican takeway are the best ones near me, but I also hit it up when out of town to find some local treats on the cheap.
Always got some pretty good stuff, though after a year or so of doing it, I did get very temporarily screwed. Went to the bagel store to pick up my order yesterday and it had closed early. Submitted a refund request with a photo of the deserted store and the sign on the door saying sorry closed early, and I had my refund before I pulled out of the parking spot. So great on them, not so great for the store not notifying me, but they usually give me more than they should and sometimes they even let me pick what goes in my order, so I'm going to let it slide.