That is an agreement allowing the broker to represent you in the purchase of real estate for the time period set forth in the contract. It is sometimes called a buyer broker contract. Exclusive right to buy means that you are agreeing to work with that broker or their designated agent exclusively to buy a property. It is very common for brokers to ask buyers to sign an agency agreement. By signing this agreement you are no longer a customer but a client and the broker now has a limited fiduciary responsibility to act in your best interests. If you are not a client but a customer the brokers responsibility to you is lessened. I suggest that you look up client vs. customer. It will spell out the differences.