What’s My House Worth? And Now? - New York Times:
"In June, for instance, more than 39 million people visited the 20 most popular real estate Web sites, a 22.4 percent increase in visitors over the same period in the previous year, according to Nielsen/NetRatings Inc. Not only that, but a lot of those people are becoming addicted. At Zillow.com, for instance, 44 percent of the site’s users visited five or more times in June, and 25 percent of them 10 or more times, according to a spokeswoman for the site."