Right, but the OP's point is that if I watch your kid for you, and you think I'm doing an OK job, then you and I can reach an arrangement separate from UberSitt

Right, but the OP's point is that if I watch your kid for you, and you think I'm doing an OK job, then you and I can reach an arrangement separate from UberSitting. Say UberSitting charges $15/hr, where I get $10/hr and they get $5/hr. When you pick up your kid, I could say "hey, if you pay me $12/hr, then you'll save $3/hr" and then I make an extra $2/hr and UberSitting makes nothing. In other words, once you make that initial connection, you don't need UberSitting anymore. This is one of the reasons why those cleaning service companies like HomeJoy have floundered, btw.