realestate.com.au put technology into their business practices to create a comprehensive look at the property prospective buyers were considering. A google maps mash-up, taking advantage of the satellite component straight off as well as being able to add in preferences such as neighborhood, price, and more, they have the incentive for users to return to their site. Add to that RSS feeds based on preference, akin to Netflix's Recommendations RSS feed, and you have regular repeat visit.
When my father worked with Real Estate in New York we discussed ideas like this; the challenge is technically adding on layers of user's desired preference surrounding the property their considering. How many different categories of information make a property that much more appealing? And, then could you go a step further by providing a rating of a property's profile matched to a user's profile derived by survey with a high degree of accuracy. Could you imagine, the city's flower district being a direct hit?