Why have an approved caterer list for a venue?

I've noticed that many venues that host special events have an "approved caterer list" and if you do not use one of those caterers, they can charge you a fee or refuse to host your event. Why is this? I guess I can see some benefits, but I'm not getting the whole picture. Also, what would be some drawbacks of doing this?Why have an approved caterer list for a venue?
To land a spot on an approved caterer list, a company usually has to prove to the venue that they are properly licensed, insured, and have not had any problems with the local health department. But the truth is, there could be any number of reasons of why a company got on an “approved” vendor list.



Before using any catering company (approved list or otherwise) do your own homework: check with the health department, make sure they are licensed and insured in your area, taste their menu options to be sure you and your guests will enjoy the food, and be sure to get some local, recent references (other than the venue that is recommending them).Why have an approved caterer list for a venue?
It will probably be the venues have trusted caterers, using their premises and not people who will not clean up afterwards and that kind of thing.



A drawback could be that those on the approved list may not be able to provide some menu items that you particularly want at your event.