I haven't considered the economics of salons, but not sure they would have the same low variable costs that allow Classpass to succeed in fitness. I certainly wish the team (and all the other YC companies) the best though considering the guts and determination it takes to give it a shot, and you are correct that I am decidedly not in their target market so I may be missing something about the idea that is gold.

Not necessarily. The long tail of integrating with the management systems those salons use is really long and it's basically a non-starter without management system integration. Add to that that those management systems have started to wise up to the need for scheduling and it's a very difficult nut to crack.

And no, those businesses will not copy appointments back and forth themselves. Small business scheduling is hard. Very hard. This isn't speculation, I've worked on a product that has pretty good traction doing exactly what they're doing. It would surprise me greatly if they've yet discovered why this problem isn't solved yet, and it isn't for lack of trying or that previous attempts haven't been executed properly.