Reviews are made for a reason. Just like friends telling you that a product is good, blogs can give you good information about products that you intend to buy. As for paid reviews, well, you'll just have to take that in mind.What's irritating are blogs that make paid reviews without even telling you that that is a paid review. It's like lying to readers. These are the type of reviews promoted by ReviewMe and similar websites.
Link: Paid Reviews are Bad.
[Note: reviewme.com seems to require this in their terms and conditions, but the blog post links to here, really encourages it]