[UweSchmidt]

Not sure about that: When the next generation doesn't know what a stamp is, and the fascination, getting a message from someone, getting glimpse into the world, has no basis, who will 'collect'?

I think it's similar to collecting old guitars; people in their financial prime buy a connection to the music and bands of the 60ies and 70ies; their children may have grown up with electronic music and can't relate.

Cars might be relatable, since you can still drive around with it, but the current fashion of having 'vintage' things may be over in 10 years.

[icebraining]

People can relate to all kinds of things that were no longer in use when they were born. Many times that foreignness can even make it more attractive, compared to someone for whom stamps were just an ordinary tool.

[pjc50]

More like vinyl collections: it becomes valuable only after it goes through a period of being untrendy enough that a lot of the stock gets thrown away.

[UweSchmidt]

...before it finally fizzles out, along with the Hipsters that brought it back in the first place!?

[sytelus]

You just wrote off entire business of trading antiques.