Right now, the only vacation rental websites that bring enough guests are Airbnb, Vrbo, and Booking.com. The other platforms don’t have many users yet. Houfy.com could grow if more hosts list their properties there, but at the moment it’s too small to compete.

I don't understand the rationale of being on Agoda, but not Booking.com if you are in the US. It's the same parent company, with Agoda being stronger in Asia. They seem to cross-list inventory, but I don't believe they do this for STRs.