Blog!
Blogs are great differentiators for brokers and agents. They let you get your point of difference across, connect with people and form relationships much easier than you can without one. They can also help you do really well with the search engines, attracting links, picking up long tail rankings, and just showing Google that there is life on your Web site and that people are interacting. If you don’t want to put a blog on your site, start guestblogging on other’s blogs. Help build your credibility and, of course, don’t forget to include a link to your site in your author bio.
Also look for other social networking opportunities that make sense for you. There are a gazillion social networks and I don’t suggest you join every one of them, however, if there’s an active community on Flickr for what you do, get involved. Facebook, Twitter and Linkedin should not be overlooked. If you can be useful in Yahoo Answers, speak up. If YouTube can help get your message out, video it up. Find the social networks targeted toward your niche and become an active member there. These tools are all chances to start conversations. Use them where they make sense.
If you’re looking to promote your brokerage Web site, above of some of the ways I’d go about doing it.