There is a qualitative difference between this and other on-demand services such as Uber in that you will never see the "here is my phone number" phenomenon in Uber.
Uber will be the eBay of this "bubble", which I think is limited to on demand startups but not startups as a whole. It'll be one of the few co's to survive, imo
I can see Postmates and Uber as the only eventual survivors in 10 years.