You've never heard of HomeAway? They and VRBO (which they own) are the 2nd and 3rd biggest players in the home sharing economy, after Airbnb.
Also worth pointing out that HomeAway only offers whole home rentals, they do not offer room-only (like Airbnb) so is not 100% part of the same 'sharing economy'.
What did I do? I found a place on AirBnB and was able to book it no problem. So I have a hard time seeing how the HomeAway / VRBO experience could come even close.