In my experience, I found online dating sites to be more for "permanent" residents of an area....
Based on my experience, you usually share emails then progress to phone calls and then plan to meet this person at a coffee shop or somewhere on "neutral" turf.... Pretty difficult to do if you're traveling the lower 48 in an RV unless,as I mentioned, you're using the RV as living quarters in a more "permanent" setting.
It bears mentioning that this in fact was what I myself was doing at the time I met my lady friend and I have since made the decision to sell the rig and settle down here in south Florida.... I had "looked" at the dating sites in this area, but did not meet my new friend there. I had actually "given up" on meeting someone and had stopped looking.
Once I let my guard down,
BAM!! There she was!!
More thoughts.... My lady friend has a long time girl friend who in fact is on one of these sites and we all sat and looked at some of her competition, to offer constructive criticism and help her "tweak" her ad.... Imagine my surprise to see some of the very same ladies from a
year ago, still on the site, so I'm not sure there's an easy answer.
Something else that's fun to do.... Do a "reverse search" and search as the opposite sex" and see what's out there that you're competing with for dates. It's hilarious, yet educational.
Lastly.... if you do write an ad, try to use something in it more original than "like walks on the beach"....
I once read an editorial on one of these sites where the gentleman said that "if everyone who mentioned walking on the beach really was on the beach there'd be NO room to move".