If you can't wait for the links-SQL version with banner system plugin, try the following solution:

I've download & modify the banner system of adcycle
(http://www.adcycle.com) and place this in my cgi-bin.
Adcycle is also a complete MySQL banner advertising system with very much options (for proffesional use)
the only thing I change is connect the advertising groups to my linkcategories (group1 is category1) etc.
the only thing to do is place the bannerscripting with the category ID in the header.txt and place this in your category.html

Now you can give advertisers the possibility to advert in one specific category with limited/unlimited clicks with a max of 10 campaigns in a limited/unlimited time.