Exclusive buyer representation agreement

[Xi Chen]

Hello All. I am a newbie investor interested in getting into commercial real estate. I recently talked to a local commercial real estate broker. After our conversation, he sent me an agreement to sign which grants him the exclusive right to represent me and will last for one year. Although I do like him during our first meeting, I am not quite ready to sign an exclusive agreement and didn't want to limit the sources of leads. 

Is such kind of agreement common and necessary in commercial real estate business? Are there any other ways to convince brokers that their interest will be protected?  I would appreciate any advice. Thanks!