That's a good point regarding licensing, I would agree they probably have to pay something, but probably not $4.75 worth of something.
I do think this would be cool on certain books, I know if they introduced a Wolverine label I'd probably like to get it for my #1 and #145 gold foil (because that's the book that got me back into comics). But it doesn't hold the same appeal as the Stan Lee labels, largely because there will be no more Stan labels. What's out there is it.
But these could potentially be perpetual since characters NEVER die in the Marvel Universe, ergo more scratch for the bottom line year over year.