I think basically marketing which causes artificial demand or short term demand spike. PCGS' "FirstStrike" doesn't mean or even remotely guarantee coins that were first struck by a mint. The only designation that I'm aware of that does guarantee first struck coins by a mint is NGC's "Numbered First Struck". There is an official paper trail (record) from a mint to NGC acknowledging that the coins shipped and received are actually the first struck by the mint. .
