As probably one of the few people posting here with actual experience with Angie's List I would say you are wrong... they're one step below a scam. They're a self deluded scam that ignores reports of companies reviewing themselves and insists that it simply isn't possible because... they "have a policy against it"
I was stunned back in early 2010 when I thought I would be a good samaritan and report a company that I knew for a fact had many accounts. Angie;s List was if anything angry at me for suggesting that a company with several very good reviews might be self reviewing. Yep they used the company's own reviews as their evidence that the company wasn't reviewing itself...
Okay I get it. Companies are buying multiple accounts and reviewing themselves which is probably a good amount of their revenue and they don't want to risk losing that revenue. After all who is so thrilled with their plumber that they want to spend money to write a review? The problem for Angies List is that they're now a public company and someone is going to expose the fact that not only does the Emperor have no clothes... he's known it all along.
Also unlike most here... I have to stock in the company, I have no desire for stock in the company and no intention of even shorting the company.