Karen....Keller Williams Realtors are all Independent Contractors. While we all are members of our Local MLS systems and also have access to KWLS, we also all have our own marketing methods and place our own advertising. The Nationwide KWLS will populate our listings to nine websites, Trulia being one. Many of us also use keyword placement to get our listings even more exposure! I also subscribe to websites which promote my listings for the towns/cities where they are located!
Keller Williams has just recently started their own listing site. MLS data used to feed into each individual agent's website. However, this has changed. We are now responsible for inputting into our local MLS as well as the KWLS site. Many agents have not done this yet, so many many listings are not in the system. You would have better luck to search the MLS.