Most listing employment agreements come with a six to twelve month contract.  Homes can take anywhere between one week and one year to sell.  This greatly depends upon the economy, geography, property location, pricing and condition of your home. 

Once a realtor has agreed to market your property, they invest a great deal of time and money in getting your home sold.  Your realtor does not recoup their investment unless your home actually sells.  The time frame is incorporated into the listing agreement to compensate for these factors.

However, extenuating circumstances do come up, and should be addressed on a case-by-case basis.  Depending on the individual situation, the realtor may or may not decide to cancel the listing.  If a cancellation agreement is an important issue for you, you should discuss it during your initial consultation with your prospective realtor.  Brokers have different philosophies regarding cancellation agreements. These range from offering a 24-hour notice cancellation for any reason, to expecting you to fulfill the terms of your contract.

Remember, if a listing gets cancelled before a house sells, the realtor will lose all money and time they invested in marketing your property.  Again, if a cancellation agreement is important to you, remember to discuss this with your agent prior to signing a listing agreement.