The report found that 36 percent of the agent-listed homes shown as active listings on Zillow and 37 percent of those on Trulia were no longer for sale. Study Finds Gaps in Online Listing Information
Zillow Sues Trulia Over Home Valuations
Personally, I don't see what they're fighting over. Both services offer specious valuation info based on limited, outdated sources. Their projected home values usually are way off. Zillow Sues Trulia Over Home Valuations