I think the idea is you can buy old stamp collections for less than face value.

E.g. this collection of 8000 stamps is $75: https://www.ebay.com/itm/396477663178

Looking at the pictures, many are more than $.01 value.

Assuming they’re uncancelled, you’ll end up multiples of your money ahead if you rip the collection apart and use it to mail stuff.

The challenge would be having enough surface area on your package to plaster on 6-cent stamps.

> The challenge would be having enough surface area on your package to plaster on 6-cent stamps.

It’s not too hard if you mail paper that can’t be folded.

Can also cover what you can and get the clerk to print you a label for the rest.

It is "legal enough" to stuff whole sheets of stamps into a pouch and attach the pouch to a parcel, if you do it at the post office and have them cancel the stamps at the counter. Let them know they can just use a Sharpie to cancel whole sheets at a time. Legal enough in the sense that my local post office lets me do it, and the local postmaster has okayed it, and the packages always make it, but I'm not entirely sure if it's 100% above-board. My record is over 800 stamps on a single Priority Mail box. Way, way more than would fit on the surface area of the box, and certainly way more than anyone could reasonably use if they actually had to apply the adhesive on the stamps.

I couldn't parse that at first either, but I think what they mean is that they don't have value as a collector's item. They still have face value, but they sell for less than that because they're not perceived as actual legal postage any longer, even though they actually are.