Hot Stamper - myth or reality?

Can someone please explain to me exactly what is a "hot stamper" LP? I figure that it's an older, original pressing of an album, but so what? If that's the case, then wouldn't every old LP be a hot stamper? Is there something special about a hot stamper pressing that differs from just an ordinary first, or older, pressing?
Some of the prices I've seen here and on other sites (Better****.com)are astronomical (and ridiculous in my opinion).
I'm beginning to think it's all a scam or a marketing ploy with not basis in reality. Unless someone can explain to me why they are better or what's so good about them.
Advice?