Rainy - when I first started doing online dating, about 6 months or so ago, I got chatting to this girl. She was lovely. Had one daughter a bit older than mine, had been single for a couple of years. Her photos were stunning, beautiful smile, and she was funny. She really 'got me', I really got her, we talked on the phone most nights for a couple of weeks as we couldn't meet up easily due to mutual childcare issues - we finished off each others sentences. It was like kismet.
Then we finally met. It was an hour of somewhat strained conversation because there just wasn't.. something. Chemistry, a spark, whatever. On the phone, by email, yes. In person, no.
So I learned to not get excited about anyone until I've met them, and not think about whether there is relationship potential until I've met them several times.
He may be lovely. He may be a nutter. You don't know until you actually know him.