No catch, that was it. So after thinking it over, and talking to a few people first, I thought about trying it. Please continue its success by carefully adhering to the instructions. In this business your product is not solid and tangible, it's a service.
Many large corporations are happy to pay big bucks for quality lists.
What you are doing is creating a service. Now, post your amended article to at least 200 newsgroups. Look at it this way. This will paste a copy of the letter into notepad so that you can add your name to the list. And start posting again.