For 30amp Trailer, install 30 or 50amp service to pole?

Hello All,

I've got electric at a private camping area and need to add service for a 30amp plug for a new 30amp travel Trailer. I heard it better to put in a 50amp outlet in and then use a 30-50amp plug to hook it up the trailer. That way I would have extra or reserve power for everything on my 30amp trailer to run.

Smart or Dumb? :-)

Andrew