Web 2.0 innovation: Skweal.
The premise is that people only vent about bad customer service or products on public sites like Yelp if either they don’t have a way to complain directly to the company (to get their problem fixed) or if they try to complain directly but are still not satisfied. So Skweal allows people to complain to one central place and they find the right person at the right company. Participating companies commit to making a strong effort to resolve the problem in the expectation that the customer will not also post about their dissatisfaction in public (but there is no guarantee/contract involved).
Would you do this, or would you rather vent in public? Is it revenge you are looking for, or satisfaction?