It is a dance, swirling and whirling until one person tires of it or moves on to a new partner. Rarely does anyone step out of bounds. It's done on the ballroom floor, to the delight of everyone. If you think you are going to find Ms. Right, or even Ms. You'll Do, well, think again.
Online romances do flourish, for all the reasons stated above.
They often crash and burn, too. Reality can be a jolt. The world is full of very lonely people, and it's safe to assume that a lot of people lurking and talking in online chat rooms are among them. For some this is forgettable play. For others, it is rehearsal.