About twenty iPods.
Walkers, a snack company, was running a contest where you could enter a draw every ten minutes, 24 hours a day, to win an iPod. They also had a website where you could get an entry code without buying anything. I was one of the few people to have unlimited texts and a phone controllable by Bluetooth at the time, so I ran a script to just spam the free entry codes. Somehow they never cottoned on.