Zillow was founded in 2004 and started its online website in 2006. Zillow boasts data on 100 million properties but is Zillow accurate. When Zillow started I used it because you didn’t have to register initially to use the product and still get the data which I thought was great. However, if you did register you were promised a better experience. I don’t know if you have to register now but Zillow has raised its standards and now offers professional tools for a fee just like realtor.com and trulia.com. But my friend, Mark Jackson of Investorcompsonline.com doesn’t believe that Zillow is the best source for data in order to arrive at the best value of the property. Is he right? Well you would certainly have to do your own due diligence and decide for yourself. However, I will say when I attended his webinar and he described his service, it was very impressive and his company offered a lot of support such as being able to call and get help to make sure your property numbers were understood by you by someone trained on his staff. I think that is awesome. Of course, you’re going to pay a monthly fee while Zillow is free. However, there may be some paid add-ons with Zillow at this point. Ultimately, you decide.