I have 187 stickers saved, back when they were new I was hoping they'd release the backwings into the sticker shop (so I'd collect them from the events and polls) but that didn't happen...now I just collect them for no reason. I hope they'll add more new or cool stuff to the wing shop...
Thus far I have 122 stickers.
I don't recall ever using them for anything, but I know I've missed several days to get some too.
I've been kinda holding out on the hope that they'll release a really cool item for 100 stickers or something.
Until then, I'm just going to horde the little bastards until they release something I actually like.
I have 89, and I know I've bought a lot of stuff. Ghost skin, a dark elf skin potion, werewolf body? Etc, etc.
I just know that they usually jump the sticker price, so if you nab the right items now, you can sell them at a higher price later on in life. Not that I need the gold, but it's something small and easy to do.