I also have my own real estate website client... To make business i gone to registered makaan.com for a free listing only... And you can't believe, since from jan I sold 3 BHk flat with expected price... Now, I'm doing paid listing to make more leads...
Are you talking about a real estate site with an international market, national market, or local market? That makes a huge difference on how you need to promote it. If you are targeting local markets start contacting real estate agents in those markets offering to do a profile page and list their homes. Let them drive the traffic to your site for you. Of course, I have no idea if your "real estate site" is showing home listings, giving information on how to invest in real estate, or offering mortgage services...and once again...all of those would change the direction of your marketing plan dramatically. Still, the movers and shakers in the real estate industry are the agents out there selling. If you can get some of the most active sellers to allow you to host profiles for them and they actually link to them, you could get some real traction quickly. Of course, that's just thinking outside the box...