In the old days of real estate, each broker had their own listings and you had to deal with that broker if you wanted to buy their listing. Then agents got the bright idea that if they shared their listings, they could waste less time and make more money. In Cumberland County, early days of cooperative brokerage meant making up scrap books of newspaper ads for houses and driving around to other offices to pick up keys. It evolved into a system of books published every other week and lock boxes on front doors with keys inside and combinations that could be given over the phone.

Now the Multiple Listing Service is an internet based database containing thousands of listings in Cumberland and surrounding counties.
 

In order to join the area's Multiple Listing Service one must be a licensed real estate broker or salesman and work for a company which is a member of a Board of Realtors. Members have access to the database of properties for sale and other services offered by  MLS.

Through rules of membership in MLS and rules governing the conduct of Realtors (members of the National Association of Realtors), a system has been established which gives members the ability to show and sell the listings of every other member of the service. The listing broker signs an agreement with the property seller, which defines the total commission that the seller will pay at the close of the sale. The listing broker then offers a part of that commission to the broker that works with the buyer. Rules of the service require members to place all residential property listed with the service, unless the seller requests otherwise.
 

Multiple listing is generally considered to be a good thing for sellers, buyers and agents. The seller benefits by having their property exposed to a wider range of customers than one agency could reach. Buyers benefit by being able to see all the available listed properties through one agent, rather than having to contact all the different companies in town. And agents benefit by being able to sell a larger inventory of properties than one agency would have available.