Real estate ads move online

Real estate advertising in 2005 will reach a total value of $1.8 billion, representing the 15.9 percent of total investments in advertising in the industry. eMarketer expects the expenditure in online ads will represent one third of the total spending by 2009.
Suddendly, the real estate sector has understood interactive works. However it would be interesting to go into further details and investigate what kind of online advertising works. I believe we should look at search engine marketing, in particular the keyword advertising model with the localization of ads.