I already have ads targeting forums (by their names).

But the problem is just there: those names can get pretty long, and all keywords together for one single banner can make a pretty long line.

So my next step is to add an extra field, with something like forum_short_name
I've tried the forumnumber, but it doesn't work (because the number is a number and not text or something?! I don't know PHP/MySQL well enough)

But a hack like this one is very good