Used stamps exchanges.

Why do people overlap stamps on envelopes? this is just another example.
I received a letter with several stamps on the envelope and I was not able to save a single one.
I think that we can do better, after all we are stamp collectors, aren't we?

Tony, in this case the stamps are not overlapped.
The sender franked the letter with one stamp of 2005 (8.00 kunas) and a edge coupling of three stamps of 2008 (3 of 0.20 kunas). Probably, the envelope was opened (at the left) and then taped with a strip of glued paper bent over the edge at the custom (?) office, which was slightly blocked the field of stamp coupling.
And I just covered my address with the lower four stamps.