How common is it on this site for men pretending to be women?

I'm sure there are a lot. I've had long running chats with people to learn that they made up everything. And these aren't salacious sex chats. Just normal day to day life chats. Boring stuff. But they made up elaborate stories with lots of characters and pictures. The attention to detail was impressive. Until at some point things just didn't add up. They didn't want money. And it wasn't some sort of fetish thing.