i think there is some house swap type programs. vrbo.org is a pretty big site but not program. good luck.
I suggest doing a google search on 'vacation rentals affiliate' and see what comes up Then click on the affiliate link. You might find yourself directed to a general affiliate site. I find that sometimes, when I want to become an affiliate of a site and click on their link, I get directed to something like commission junction or linkshare You might turn up the same type of info for vacation rentals