We are really starting to love your services. Especially how you stagger the deliveries over time.
I'm pretty stunned at how well your service works -- it's easily one of the most intuitive applications I've ever used. Most important, it seems to work! It took me only about an hour to get a newsletter through the test point. My highest compliments.
...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.