Wife & I have owned a RV park in Texas for just over 18 years. It was to be my retirement project after working for a large international company for 40 years. Turned into a long-term project with 4 of my 5 immediate family members involved.
We were lucky to find this dilapidated RV park for which the only thing going for it was it's proximity to a very large Texas city.
IMHO be very, very careful about the location. It can make or break very quickly. Also, any water attraction (lake, river, etc) helps improve occupancy rates.
Over time, through a lot of very hard but rewarding work, we have turned this park into one to be proud of. 100% full year round, typically with a waiting list for longer-term sites.
We, too went into this venture planning on only over-nighters or weekly guests. Quickly learned that does not pay off. We do a lot of short-term, but found we needed the stable long-term guests to pay the bills. With short-term you are at the mercy of too many uncontrollable factors; price of fuel being one. Amazing how volume can increase/decrease relating to cost of fuel.
I personally would not recommend absentee ownership of an RV park. Also, I would not buy a RV park if I couldn't perform most maint. tasks, i.e., plumbing and electrical repairs mainly. Furtunately, in Texas, unless you are located in a controlling municipality, the laws allow you, as owner, to repair anything, however if you have electrical repairs done by others, they must be licensed in the state.
Our park is in a MUD district; I would not buy a park on a septic
system.
Other moneh-makers: propane, ice, park cabins, a few RV necessities (coax cables, water hoses, sewer hookup needs, etc.)
We are a member of ARVC (National Association of Campground Owners), and a few years ago they published an article on constructing a new RV park. They came up with a figure of $12,000 per site (not counting cost of land) to build roads and all the infrastructure items you need to provide a potentially successful park.
Last item; IMHO the major downside of owning a RV park is the fact it ties you down and makes extended traveling impossible.
I know this is long, but hope it gives you a few more things to think about.