Probably most people don't notice or care, but Facebook introduces so many artifacts into jpegs, there's got to be room for a startup that actually doesn't compress the crap out of images.
Facebook is a place for photos of people's faces, really. If the artifacts prevent you from seeing someone's face, the picture is probably too small to begin with. Putting other kinds of photos on Facebook (like, say, Cinnabon(TM)) always baffled me, but people do it anyway.
CD systems' speakers (when not Hi-Fi) have worse sound than middle of the road headphones, and cassette had like 8 bit definition (and noise, wow, flutter and other nice stuff to degrade the sound).
As soon as they find they don't become Robert Cappa or Steve McCurry overnight, that fad will come to pass...