Reseller
My roommate at the time bought a car with his Best Buy bucks. He sent in a ton of self-addressed stamped envelopes to get game pieces. Each game piece had at least $1 of BB money, but some had $3. There’s a law in Vermont that doesn’t require the sender to provide postage for the return envelope on a SASE.
So he had all his game pieces mailed to a PO box in Vermont, thus saving 37 cents per entry. Then he had all the game pieces shipped to his home in bulk. Much cheaper than spending 37 cents per entry. Once he got his game pieces, he peeled all of them, collected his Best Buy bucks, and went around buying MP3 players from stores.
Best Buy got wise to this pretty quickly and had a $200 spending limit per day, so he’d travel around the entire metro area hitting every single Best Buy and spending $200 at each one. Then he sold them on eBay as new in box for like $10-$20 off the retail price. I think he made around $10,000. It was a lot of work, but it beats a job I guess.