Online chatting is certainly no way to guarantee the validity of the other party, but if you talk to someone every day for a few months, you get some idea at least.I don't think online is a barometer to the success or failure of a first meet.
Many guys who are just after a bit of fun (for them) get impatient if the subby won't meet them in the first week or so. If they're serious, they won't care how long it takes. The same may well be said for Dommes, I wouldn't know.
I met someone last year- we started PMing each other, & then moved to chatting. We talked about the possibility of meeting within a month or so, but decided it was wise to get to know each other first.
We chatted pretty much every day, talked about our expectations- & most importantly the limitations. It was well over 6 months before we met.
The initial meeting was in the foyer of a big hotel- we went to a nearby coffee shop while she made up her mind whether I was genuine or not....
We then moved to a holiday unit we'd prebooked, & spent the first day just getting to know each other & hanging out.
I made sure she had a pre-arranged call to a friend. It's essential IMO to tell a trusted friend what your plans are including where you'll be staying, & if they don't hear from you at a particular time- preferably every day, they know there's a problem.
The next day, when we were fairly comfortable (well I was anyway) we um....well that's none of your business....
Anyway, the whole experience was every bit as good as I'd imagined- rather more in fact. She's a helluva nice person, & we still chat pretty much every day. Both of us are taken, plus I'm married, so there was never an option to stay together.
However- we may well do it again someday.