Since we have a very hot real estate market in many parts of the country, in some cases real estate agents are not even putting listings on the MLS, the multiple list service and or they are not even listing the property for sale. In essence, they are hoarding sellers in an attempt to get both sides of the sale to increase their commission income. There is nothing illegal about doing this; but once a property is officially for sale as a listing, it really should be put on the MLS to get maximum exposure.
In some cases a real estate agent may know of someone that might be interested in selling the property at the right price; but is not actively looking to sell the property for the moment. In that situation, if an agent brings a buyer to the table without listing the property at all, there is nothing illegitimate about that transaction. Of course, the commission will be subject to negotiation when that happens. It is not likely that a seller will pay a full commission in that quick sale scenario.
Greed is obviously at play in Pocket or Whisper listing. The real estate agent is attempting to keep a great home that will sell quickly off the market even though it may have officially been listed. Sometimes, the real estate agent will wait a week or two before putting it on the MLS to work with any potential buyers that they know of. Again, nothing illegal; but in this market where listing sometimes get multiple offers above the list price; not listing on the MLS would prevent a bidding war, which is not in the best interest of the seller. In any case, real estate agents often get creative to maximize their commission earnings, which is all fine provided they abide by the law.
At Paragon, we work clients to sell and buy homes all over the country. When selling a home, we work to get our clients the highest price possible so we would insist that the property after listing be placed on the MLS because we know that competition is the best way to get the highest price.