Have you ever successfully gotten a free product from a "participation required" website?

This “participation required” type of “scam” for free products became fairly popular with the “free iPods” about five years ago. The websites require you to click through tons of offers and choose at least one to sign up for (e.g., a magazine subscription). Sometimes, they also require you to have five friends do the same.

Have you ever actually tried one of these? If so, how has it turned out?