Zillow and its affiliates control over 70% of the market, which can only be characterized as a monopolistic position. Few years ago, Zillow allowed owner to post their houses for sale in a more or less fair fashion. But Zillow was a big threat to the monopolistic position of the NAR and was in a way eroding their stronghold on the market, adding the fact that Zillow also controlled most of the listing market. The NAR (National Association of Realtors) then made a deal with Zillow, and now Zillow hides all the listings of forsalebyowner -- basically fsbo have no visibility whatsoever and the vast majority of buyers who use Zillow simply will never find them. Trulia belongs to Zillow and simply does not allow non-realtors to list there. In other words, NAR, Zillow et al deploy unfair practices to artificially control the market and maintain their stronghold on the market by artificial and unfair practices and means which then can only be characterized as a monopolistic position -- it seems that our anti-trust laws (Sherman anti-trust act) have no validity any longer.
All in all, one is going to waste ones' time posting a property on Zillow. It is completely hidden and the only ones who know about that hidden features are realtors -- and you will only receive realtors' calls, 99% of the potential buyers will never see your listing. One of the States Attorney Generals need to look into that clear-cut violation of the Sherman Anti-Trust Act.