I did a search here, and found some info but I'm wondering if I'm still missing something. Here's what I got from searching: Stamps.com does the following: 1. Prints mailing address on envelope. 2. Prints return address on envelope. 3. Prints postage on envelope. I currently use envelopes with the window, so the customers name and address appear in the window. And I print sheets of return address labels in advance. I buy enough stamps at a time so that I don't have to go to the post office too often. So after printing the invoice, I stick the stamp and return address label on, which takes no real time (it's actually the fastest part of invoicing!! LOL!). So is the only advantage of Stamps.com the fact that I wouldn't have to go to the post office?? Or is there more to it that I'm missing? Thanks in advance.