[ck2]

Yeah, all the ones that start with "I received the complimentary product" in some form.

That's a bogus review, it's paid. You might argue free product is not payment but the IRS would then like to have a word with you (ask the people who got "free" cars from Oprah).

[tass]

This is fairly anecdotal, but I've read some people's experiences with free products for reviews. They received products while they were giving good reviews. The products stopped once a bad review was posted.

Amazon also gives free products for review (Amazon Vine) but these are made very clear with a banner above the review, and will remain part of the program so long as they continue to receive a high number of 'helpful' votes on their reviews.