If you haven't heard about this, you should probably study it. The same thing that's happened to a number of college students and families who have illegally downloaded music and been fined hundreds of thousands of dollars will inevitably happen to a few small-time bloggers who like getting free stuff and want to earn a little from their blogs on the side.
If you haven't heard about this and can't get past the guy's enormous head (I know-mesmerizing), here are the basics: you have to disclose if you're endorsing something on your blog and are being compensated for it, either in free items, money or both; and, you are just as liable for the things you say about those products as the companies are. You can't say they cure acne, make your head look smaller, etc., if you don't have proof that it does. If you're going to advertise, you have to go by the advertising rules that everyone else does.
As far as I've seen, people generally don't care for the new legislation, but I have to say, I like it. I can't stand how too many blogs are turning from informational or entertaining posts to more and more and more product promotions. I've seen at least two blogs that have gone almost entirely to sponsored posts.
I also hate to find out that the opinion of a blogger that you like is actually being routed directly from a corporation's mouth. It feels a little like a betrayal of the blog's readers. If you're doing paid posting, most paid posting companies require that you disclose all sponsored posts. They also allow you to write a negative post if you want, if that's how you really feel about the product. I did a little of this more than a year ago to monetize Ye Olde Blogge a little. I stopped doing it after a little while, but I have nothing against those who do it. When corporations step in and offer products directly, however, that's when things can get murky.
Disclosure is easy, and it keeps the blogger honest. If you get a few free products and the reviews you write are disclosed as being sponsored or in exchange for free stuff, I think it probably keeps bloggers from gushing about how great the stuff is in order to get more stuff. This means that fewer people will get a false idea about stuff and less money will be wasted. If you don't disclose, it's almost like you want the economy to tank. And then, of course, the terrorists win.