It sounds like Amazon strong arms these companies into ONLY serving them. FTA: "The incident is notable as it appears to be the first public example in the United States of Amazon delivery service partners, small businesses that deliver packages exclusively for Amazon" This is the program for Amazon Delivery Service Partners https://logistics.amazon.com/ Seems to me it's basically Amazon Flex but for people with... - Source: Hacker News / almost 3 years ago

I'll have approx 10-20 products, would like to have live inventory, and be able to accept CC payments and initiate shipping labels through USPS or stamps.com type of thing. The idea would be that the functionality of the site minimizes the labor of order fulfillment. I have an etsy store for 4 products and like the way that is done. Unfortunately, the products are probably not appropriate for Shopify or Etsy type... Source: 6 months ago

When I opened up the order history in stamps.com I noticed that there were dupliacte labels purchased for the same order number. Then I went over to shipstation to see if the duplicate shipping label were imported and there was no record of it being there at all. So stamps.com would occasionaly purchase 2-4 labels for one order but only send one of the labels through to shipstaion. Since we never log in to... Source: 6 months ago

I have been very happy with my Shipstation rates, but the incredible customer service I get direct with a UPS rep on my other accounts is second to none. I do hate having to constantly reload a stamps.com balance and I would much prefer invoice billing like I get direct with UPS. Source: 7 months ago

The cost to ship the box is $22.80 (and would be cheaper if you use something like stamps.com) and the 3.43 gallons of pumice would cost $1.67, making your total cost to buy and ship $24.47, which is $7.33/gallon. Source: 11 months ago

My USPS Informed Delivery email says I have a package from stamps.com waiting for me. I didn't order anything from stamps.com. Source: 11 months ago