I have been using LetterTrack's service for several months and I am extremely pleased. I sell on eBay and this service assists me with mail that is sent using postage only stamps. This is not tracking provided by or available with usps, but a barcode that with receives scans at usps sorting facilities. If you upload your customers information properly they will receive email notifications each time the item receives a scan. Customers then know there item has been mailed via the scan and not simply via the seller. The service has been great for me, the cost is minimal and my customers can see the progress of their item while in transit. This progress is only visible through lettertrack, not usps. They will need to use the link they receive in the emails. Sometimes pieces will miss scans, and that is to be expected, but the percentage is very low and 99.9% of my pieces have been delivered even without scans. Mail does get lost, this service is not going to prevent that, that is a usps problem. I do not tell my customers about the service in advance. I do not charge them for it and I do not want their expectations to exceed the service that is available. I have received very nice messages from customers who were amazed with the service of lettertrack. Not to mention the customer service provided by the company is outstanding!! So to sum it up: A GREAT SERVICE, LOW COST, HAPPY CUSTOMERS ALL EQUALS A SUCCESSFUL BUSINESS!