Sure, it's allowed. Our members are pretty smart. If a person has a signature link full of "click bank" stuff or if this member is making simple one line posts (like, "I agree" or "Cute dog" or something like that) without actually making an effort to participate, they aren't going to click.
A participating member who gets to know us and is making "valuable" posts, our members are likely to click on signature links.
So, have at it. Get to know us. And enjoy your stay here