E-trader links

Hey

I'm a very new member on these forums. I'm hoping you can help me on this one: Are members allowed to use e-trader links on Lefora forums? In other words, are they allowed to post links for which they receive money each time someone clicks on it? As far as I know, most forums forbid it. I've been invited to a forum hosted on Lefora, but I've seen a lot of these kinds of links on that forum. Is that ok? I'm scared and I don't really want to get into something illegal.

Thanks!