OFF MARKET PROPERTY are properties that are for sale but not listed on any Multiple Listing Service (MLS). Because these properties are not listed with the MLS, other sites such as Zillow, Trulia Realtor.com do not have the property details either.
As a buyer, the benefit of knowing about these properties is you avoid the sense of URGENCY to make a quick decision to purchase a property and you are often not competing against multiple offers at the same time. This not only ensures you wont have to over pay for your new home, it also gives you more time to do your due diligence on the property as well.
As a seller of an OFF MARKET PROPERTY, you get the benefit of Bench Testing the Market to see what kind of appetite there is for your home. This process also allows you to avoid the misleading Days On Market that many Buyers and their Buying Agents use against you, the Seller.