As David has pointed out a small site is more of a hobby than a business and it is very hard work to keep a CL running with a steady flow of customers.
You realy have to already have a plot of ground in your hands to make it work.
I've looked at this project myself several times and have drawn up business plans for submission to various banks and they have all been turned down as too lower profit on the capital investment required and also the other stumbbling block was the need for a long term start up loan that to be repayable would of needed to run for more than ten years, which is the normal term of a business loan.
Perhaps when my rich uncle decides to dispose of the family farm and distribute the assets between the grand children, I might be able to obtain a field and try again.
Not all caravan sites are seeing the upturn of visitors that we hear of in the economic crisis. The one where we have our van on a seasonal pitch is having no increase in casual tourers and even the seasonals are not comming down as much. I expect that coastal sites are fairing better, but again they often have to make a years salary in six months.
I will try to do a site when I have a plot of land to start with and the relevant planning permissions approoved. Once these two monumental obsicales have been surmounted, I can then focus on building a park that will attract visitors and keep them coming back. All this will take a decade to achieve but it just might be worthwhile.
I know of one welsh farm site where the farmer diversified and developed a caravan park for about 100 pitches that has no major facilities other than a toilet block, and he has made a success of his project over many years of hard work. He diversified on the site by allowing a contingent of campers who enjoy hang gliding and micro flight activities to use the field next to the site as a landing strip. He is also very handy for the royal welsh show and during the show he shuts his site to all but campers for the show which again brings a welcome income to him. The farm is still running and again he allows the campers to roam his land and walk where they please.
So a small site can work, but you have to have the cards stacked in your favor and be prepared for a lot of hardwork. Being a very competent builder also helps.
Regards.
Steve L.