I noticed that you mentioned a "Trulia competitor" and I don't know which website you saw this on. However, I will tell you that Zillow posts EVERY HOUSE on their website....regardless of it being for sale or not. On each house they will list what they think the value of the home is (based on various factors, that may or may not be accurate) which they call a Zestimate. It is slightly mis-leading as it does look like the home is for sale, when in fact it's not. Actually, if you look up your own personal home on Zillow it will likely look like your home is for sale too.
I hope that this information is helpful to you as you are looking at the real estate market in your area. If you would like the most accurate information (and the information that a real estate appraiser will review), you should contact a REALTOR to represent you. Your REALTOR can help you determine the current market value of your home and assist you with marketing your home for sale, and when you have it sold they can assist you with purchasing your next home as well.
If you would like further information about real estate in your area, please let us know. Our agents will be happy to assist you with all of your real estate needs. Have a great day!
Coldwell Banker Jane Henry Realtors
North Texas Top Team, Realtors