[budumol]

It depends I guess on how you get your traffic from facebook. If it's all "legit" meaning you'd be confortable explaining to one of your competitor how you did it because he's unlikely to reproduce it overnight or report you to google, then it's fine.
For instance if all your traffic comes from your facebook fan page, then fine I think.

If it comes from facebook ads I'm not sure, I don't know.

But if it's something else like paying someone who has a trick, then no of course.