This is not meant to be a definitive masterpiece. It is a subjective opinion based loosely on anecdotal evidence and hearsay story-telling :)
Internet dating can lead to people meeting each other. Both will have preconceptions based upon their previous text conversation, any phone calls they have shared and images that they have swapped with each other.
Upon meeting face-to-face, there are seven distinct F-Zones that appear to exist.
1 - Fear Zone.
One (or both) can not stand the other. You feel creepy around them and just want to leave. You avoid all social niceties just to get the hell out of there and run. This may be a rare occurrence, but take warning and save yourself.
2 - Formal Zone.
You don't click with each other. It's not going to happen. Yet, you are both civil enough to finish your drink and spend the ten minutes listening to each other's brief run-down of their day. You thank each other and leave. Follow-up contact is usually non-existent from the Formal Zone.
3 - Friend Zone.
You mix well enough to be polite and happy. There may be some interest, but nothing too heavy or promising. It's a safe spot to be put and usually doesn't permit much more progression. Is there anything wrong with just finding a friend?
4 - Flirt Zone.
You flirt with each other. There is something there and it may happen. The Flirt Zone is the middle zone for a reason. You won't stay in the Flirt Zone too long, as you either progress to the next zone or ultimately, you fall back to the Friend Zone. The Flirt Zone is a fleeting transitional zone that should not be a permanent stop, unless you both enjoy the perpetual tease.
5 - Fun Zone.
You both click and the mutual attraction leads to more. It's physical and it's on. It might start lightly and doesn't need to progress to being too heavy, but you're both definitely having some fun with each other.
6 - Fuck Zone.
The Friend Zone is a safer form of the Fuck Zone. The Friend Zone might have involved some heavy touching and groping, but the Fuck Zone is full-on, strip the clothes off and go for it.
7 - Future Zone.
You both might be looking for a future together? There's a rare connection if you're open to it.
Whatever you do and whichever F-Zone you find yourself in, just be smart and safe about it. If you are both upfront with each other about what you seek, you might enjoy it more - especially if you can both mutually agree to be in the same zone from Friend upwards. :)