The big difference is that the services are also delivered by phone. With Lyft, Uber, Exec, etc etc, the people providing the services are not employees of the startup but independent contractors using the app to get referred to customers. Instead of going into work, having some guy tell them who their customer is and taking a cut, they have the app tell them who their customer is and take a smaller cut.
So the benefit is really to the service provider?
However this relies on changing user behaviour, so I guess service providers using such services will be all able to charge lower prices?
That is the big difference.