People are buying comic books like never before thanks to the movie adaptations that are making billions in the box office, and yet the comic industry still struggles to stay afloat.
Nowadays people decide which series to read based on reviews online, so their opinions aren't swayed by a snazzy looking cover, but back in the day a gimmick cover was the ultimate way to sell comic books.
Guest artists were often brought in to create the bold illustrations on the cover, and this art was designed to make readers feel like that issue was something they couldn't live without.
Unfortunately, many companies also relied too heavily on needlessly gimmicky covers to sell their books, like The Amazing Spider-Man issue 400 which was supposed to look like a tombstone but wound up looking like a blurry mess.
See The All Time Greatest Comic Book Gimmick Covers here and the All Time Worst Comic Book Gimmick Covers here