As of the last set of publicly available data from Statista in February 2016, Real Estate traffic is dominated by Zillow at 24.7%, followed by Realtor.com at 11.1%, followed by Trulia at 9.9%, with a fast drop off to all the following sites. That means that the top 3 sites make up 45.7% of all real estate online traffic. That also means that the rest of the 200 websites on this list make up the other 54.3% of traffic, largely made up of brokerage sites and local search sites. Here are the top 9 sites by traffic from Statista:
Re/Max Real Estate 1.2%
Since the search market is so fragmented, it is important to list your home in a place where it will be listed on all of these sites. That is the primary reason to have an MLS listing as the MLS is used as the data source for most of these websites. If you list your home on the MLS, it will be pushed to all the search sites and you don't have to worry about guessing what site your neighbors are using to search for homes.