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This is definitely a good answer and the way to be thinking about it. You're never going to outrank Z/T/HP/RDC based off domain authority if you're a small site. First you need to have your onpage SEO absolutely dialied (H1s/H2s/keyword mentions (in this case address)). Then as Matt suggested pull in other content that is related to that listing or area, such as pricing and information about other homes selling or being listed in that area. The more of this rich content you have, the more you will be able to compete. But as others have said, you also need to get more links. If I were you, I'd find aggregators that you can form partnerships with as the originator of the content. Qualifications: I ran SEO at HotPads and Trulia Rentals for a while