Yep, they've done this for a while now, probably 10 years or close to it. The only catch is that as far as I know, unless they've changed something, its' only supplies for people who use Priority mail. I used to use their supplies a LOT, but most of what I sell these days are small and light enough that using Priority mail would double my cost, even with using free supplies. If you sell stuff that needs to go Priority mail, though, you should be making use of the free USPS supplies, though, as much as possible. Those expenses for things you have to have, like shipping boxes or padded mailers, shipping/packaging tape, bubble wrap or peanuts, those are what can add up and cut into your profit. Since I ship small parts for guitars for the most part, these are small enough to go into a 5X7 or 6X8 inch mailer, so I have started buying mailers by the case of 500, and storing them in the large rubbermaid totes except for about 40 at a time that I keep in a drawer under my shipping bench. You'll find that by buying mailers 250 or 500 at a time, you can get them for FAR less than you can by buying them at Dollar store or Walmart, and as long as you store them well, they never go bad. A 6x8 mailer from Walmart will run you about 70 cents. Buying them in bulk, I occasionally get them for less than 10 cents. When you multiply that difference in price times 500 mailers, you save a pile of money, and that's free money in your pocket, even if it takes you a year or more to go through that many mailers. Same with packaging tape, buy it in bulk and save money.
I've also been a "buy a label printer and stop using paper and tape for labels" guy.... because tape is expensive, although paper isn't that expensive, but now that you can get a QR code sent to your phone for labels, if you aren't shipping a lot of packages, you can just give USPS the QR code and they'll print your labels out for you at the post office. Another way to save a little. It all adds up over time.
