I had a one month free trial that included a $5.00 credit. I only used it once. My package was over $5.00 so I had to transfer money into my stamps.com account to cover the additional cost. They're minimum 'deposit' was $10 so my money sat there unused until I cancelled. When I did finally cancel (before the trial was up), I had to wait a few weeks for them to send me a check for the credit.
When I called to cancel, the girl talked me into another free month so I said sure, why not. I never used it so after a few weeks I called again to cancel for good. They tried to offer me a lower monthly rate, which was stupid because if I only used it once in 2 months why would I pay to keep the service?
Anyway, the rate I was quoted at the time was $15 a month, but they discounted it to $10 a month if I stayed with them. I think that's crazy, considering I can print postage for free with Paypal and usps.com.
