Bro Sir Dennis,
Hey, I too have been chatting with thai girls from social website! Same question as bro etc88, have you met them?
For me, I have been really lucky and have managed to go out wth a few of them. Since 2009, I have been to bkk a few times and have always met girls I chatted via the web. Even been lucky with some of them!

In my humble opinion, I dont think they are more shy,. I guess it's really just a matter of luck.
I am going next week and this time with a friend and for a longer trip. Have arranged to meet (hopefully) a few girls and go clubbing with them. Wish me luck!
the girls I have met varies in their profession. From unemployed to cafe owners to even insurance agents!
I am no expert and just sharing my experience.