Competitors and vacation rental market

Today I counted how many portals are out there for vacation rentals. I counted 51 in USA. Some are really big and some are not that big. I am pretty sure there are more, I just got tired on the page 5 of the search.
So what is it I need to do to make my site the best?
I don't really need to invent the weel, all owners need are inquiry and fast help.
1. Customer service.
I hear all the time on how frustrated owner can be if there is something on the listing that he can not do and he has no help to do it. Our site definitely is in need of good HELP section. I started one here: HELP, so this is a start.
2. Inquiries.
Currently we are researching on all possible feeds to classifieds and directories. After we did HTML make-over we lost in traffic. But XML feeds and bulk submissions should bring it back. And also the new HTML coding should kick in soon. We hade 400 visitors yesterday, our goal is to have 2K by summer.