Max Householder I was talking to someone recently who has had some good luck with this. However, they didn't develop the property into an RV site, it was just just ready to go as-is. It was a flat, vacant parcel with enough room to park an RV, the local code didn't have any issues with parking an RV on a short-term basis, and it was in an area where RV campers wanted to be.
If you're using a site like hipcamp (the airbnb for RVers), you're usually not going to make a ton of money this way, but you can make some smaller trickles of fairly passive income. In other words, if you can get a good deal on a property that is already set up for an RV (without spending a small fortune to develop the property), it could make sense.
Of course, every deal is its own unique thing... there's probably a time and place where it does make sense to spend some money developing it. I just haven't encountered that situation yet in the very few conversations I've had on the subject.
If you're able to find a deal where development cost does make sense, be sure to post your experience here! I'm sure we'd all love to hear about it.