In blog land, you get hit up by companies all the time. For what is essentially free marketing. That's not how they present it to you, of course. But essentially I, the blogger, get nothing. So I, the blogger, generally say no.
When I got an offer from Adam at The Bouqs, it was simple and direct: "we'll send you flowers if you'll commit to reviewing them." Done. No fine print. No BS. And that's how they seem to function across the board.