I am a Master Plumber with 38 years in the trade. I was contacted many times by AL to advertise on there site.
After reviewing the matter I decided against it. There are to many red flags. The input from members are not scrutinized enough and there is to much room for abuse. To me it looked like a giant pity party.
A complaint at the BBB I consider much more legitimate. A person who complains there has to submit it in writing along with their name and address and supporting documents. The contractor has a right and opportunity to respond. All of that information is there for anyone who wants to see.
Sort of the American way in that we all have a right to confront our accusers. If you want to have success with a contractor first listen to what your gut tells you. Then ask many people you know and trust for recommendations. Do read any information at the BBB and state licensing boards and AG office ( but if you feel need to do this or look on a web site then you should probably look for someone else).
On your first meeting was the contractor on time? Did he call you to let you that he was on his way? If he didn't do not hire him. Trust me on this.
Ask them right to there face if they have ever failed to complete a contract or had any major complaints and watch their reaction. The best one though is to look in their truck when they come to your house and look at how they are dressed.
If they and there truck is a mess then the work they do for you and the respect that they show for you and your home will probably be the same. I have ZERO complaints against my company.