Fame
Etsy sellers generally live in pleasant obscurity, with no need to hire bodyguards to defend them from the paparazzi every time they run out to buy groceries. Still, some people do make the leap to fame. You go from an unknown illustrator to one of the Coolest Artists on Etsy. Or your hand-knit scarves could end up in the Sunday New York Times' Fashion & Style section.
It's been known to happen. Just...don't bank on it, okay?