This actually does work, seen it myself work.

:0)

They always said it would damage the pins.

Damn

Some guy in the company must have had bad experience with blowing into cartridges or somethin like that

i've done that with gba games. sometimes the startup screen wouldn't play all the way or would have pieces missing or out of place. only way to fix it was blowing in the cartridge and then it worked just fine

it's actually for luck

Sonic 3 proved that this works