I went to dwellable.com to check it out and was surprised to find my property already listed there (with a link to the free website I actually listed on)!  This explains how they work:

Surprised to see your rental on Dwellable?

Dwellable is just like Google - we're a vacation rental search site. We show high quality listings from other web sites. When visitors want to book a rental, we send themdirectly to your web site to complete the booking. You can update or remove your listings at any time.

We're friendly, don't worry! We drive you traffic and increase sales.

If you want your listings to perform better on Dwellable, you can improve them by adding high resolution photos. Again, this is all free! Contact us for more information.

Don't forget, with Dwellable your houses also appear on Dwellable for iPad. There are over 55 million iPads out there.