Will multiple websites help get found in Search Engines? Absolutely! The more the better.
BUT...they need to be sites that get high rankings too.
I have around 15 websites but the real goal of my multi-site strategy is to get my Top 2 sites get better placement in the SERPs. Last month, my SloCountyHomes.com site received 8045 referrers from search engine lookups. My LocalLinks.com site had 5695 referrers. They are optomized for different search terms and show up in different SERPs.
I have spent a lot of time on the sites to get them to where they are and it's finally paying off. My business model is a bit different than the San Diego reference. My business is 100% Internet and the leads I get I refer to agents on my Team. I do the techie piece of the overall service to clients and my team does the personal service. I also help them on how to systems to manage leads as I do a referral on the leads so if they don't close them, neither of us get paid.
Keith Byrd
www.SloCountyHomes.com