As we all know, ranking highly on Google is the "ultimate" in internet marketing and web-presence since Google does have the largest market share of online searchers.  So pay attention as Google states: 

"The heart of our software is PageRank^TM, a system for ranking web pages developed by our founders Larry Page and Sergey Brinat Stanford University. And while we have dozens of engineers working to improve every aspect of Google on a daily basis, PageRank continues to play a central role in many of our web search tools."

PageRank Explained

"PageRank relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page's value. In essence, Google interprets a link from page A to page B as a vote, by page A, for page B. But, Google looks at considerably more than the sheer volume of votes, or links a page receives; for example, it also analyzes the page that casts the vote. Votes cast by pages that are themselves "important" weigh more heavily and help to make other pages "important." Using these and other factors, Google provides its views on pages' relative importance."

Google goes on to explain: 

"Of course, important pages mean nothing to you if they don't match your query. So, Google combines PageRank with sophisticated text-matching techniques to find pages that are both important and relevant to your search. Google goes far beyond the number of times a term appears on a page and examines dozens of aspects of the page's content (and the content of the pages linking to it) to determine if it's a good match for your query."

Hope this helps some real estate websites!