A lot of Web sites allow consumers to rate and review a businesses, but readers cannot be sure who really is writing the reviews. Think about it. A reviewer can be the business owners/workers or a friend of theirs or a competitor can write a negative review of a competing business.
When searching out the right vendor for your wedding, get recommendations from friends and family as well as other vendors that you're meeting with or already hired. And remember that reviews are subjective. Someone might think the work of one vendor is horrible, while you might love it.
Do your own research and meet with people that you like, regardless of whether a co-worker told you that the staff was hard to work with or they didn't like their work. Make your own decision based on your communications with a business and opinion of their work.