Your service sounds too good to be true. I'm with Topica now and they're okay but I can't send my subscribers to a custom "thank you for subscribing" webpage once they subscribe.
Your service is absolutely hands down the most cost effective marketing tool I have ever seen - and your service just gets better and better!
I've been trying to find a provider like yours for months. Something I can afford and get support during the evening and night time hours when I do most of my web work. Benchmark is too expensive and they go home at 3:00pm my time with no support available.