I'm sure there are reasons... an agent that's a friend, falling for the "pitch", low commission...
But, there is a difference. The difference is this... chances are that another agent is going to do the actual "selling" of your listing, i.e. bring the buyer to the table. . It is going to more or likely take an AGENT to sell your property. Someone who can get a potential buyer through the front door and show them around. Do YOU want to be available at all times to do this?? Probably not.
Out of town agents do not have the same access. They are usually members of a different multiple listing service. (In case you do not know, a multiple listing service is a database that real estate agencies belong to. It pretty much makes for a "one stop shopping" place for a buyer. The member agencies co-broker all the listings and sell each other's listings this way. It saves a buyer a lot of time and trouble dealing with one agent rather than driving all over town calling from sign after sign after sign). Here is where the LOCAL multiple listing service comes in handy..... ASK THAT QUESTION!!! "Will all the local agents have easy access to my home?" Local agents here that are MEMBERS of the local board have a super duper keysafe key that allows them access to the homes listed on the multilist. The keysafe is like a small vault that hangs on either your doorknob, or the porch railing and it takes an electronic key to open it. These electronic keys each have a unique password, specific to that particular Realtor®. The key has to be downloaded every three days (in our case), or the key becomes inoperable. The download process is also an upload process, in that all the homes opened with that key are uploaded to the listing agent's database, so your agent knows which agents have been accessing your home. It's a pretty good system that we have... and pretty safe too.
If your listing agent is a local member, he is basically enlisting the help of almost all the other agents in town to help sell your property. In our case that's around 300 agents with each one of them having a set of buyers. These local agents have access to your property. These local agents have a very important "leg up" on out of town agents... "LOCAL KNOWLEDGE". They can access more reports of sales and comps that an out of towner and more quickly. In town and local agents really have an advantage when listing property.
Occasionally, there will be an out of town agency's listing close by... It is not on my normal radar so I will probably miss it (I look every DAY at our listings that are held by our local agents, and so do most of the others in town). It will be more than likely a hassle to get inside the property as they will not have the same key safe. The seller might have to be present in order to show the property (which is a big turn-off to most buyers). Yep, an out of town multiple listing service might have more members, and this might be a good pitch... but they do NOT have all those agents actively showing properties close to your place that you wish to sell.