I'm in the online real estate business as well (
www.SeattleRentals.com and
www.PortlandRentals.com) and Rent.com is a strange competitor for us.
For every renter that Rent.com sends to an apartment building, the property owes a commission of a few hundred bucks. Rent.com keeps the majority of that money but gives $100 over to the renter.
Problem is, renters are so keen on getting $100 that they'll say that they found their apartment on Rent.com even when they didn't just to get their reward.
I've heard apartment buildings say that they end up having to unnecessarily fork out referral commissions to Rent.com pretty regularly. It's a tough call for the buildings - they obviously want the renters, but each lead does cost them a few hundred dollars, and half the time they can't even be sure it's legitimate.
Also since the ads are "brochure ads" (generic info about the property and not current vacancies), the renter doesn't get to see what's actually available - they have to call or email to find out if the property has anything.
In our Northwest rental market vacancy rates are dropping at a crazy rate - fewer and fewer apartments are available. So this means a lot of wasted time for renters who have to call through all the ads to find out if there's a property out there that has that studio apartment for $650 a month that they really want. And wasted time for property managers answering those calls.
That being said, the Rent.com model still seems like a great idea for a business - fork out a bit of your revenue back to your target market and you create a dedicated following.
Renters always tell us that they love our website over Rent.com's (we have current vacancy info, no login required, no banners or pop-ups, etc - all the things that renters love) and yes, we've got our own following with over 6 million hits/month on our sites, but if you think about it, who doesn't want free money? It's really tough to compete with that.