...having found your service by chance, we've been completely happy and pretty surprised actually. You offer a lot of features, with a very reasonable & logical rate system. ...How much your service will help is possibly beyond your understanding, but I'm sure you've heard that from other people using your service.
You guys rock!
I think this is an excellent way to acquire paying customers AND will give many potential users the option to see if they can build a decent subscribership without having to front the $250 or more that would be needed for ListBuilder.