I'm currently working on a website for a friend where she is offering space for baby-related businesses to advertise and has various categories with a gallery of 150x150 ads on each page for that category. Here's what it looks like so far - http://imghostr.me/images/Nesa.png
She has three absolute musts for the site.
1. Ads must rotate so they aren't in the same place all the time.
2. When clicked, the ads must direct the visitor direct to the advertisers website.
3. An option to enter when each ad expires.
I'm struggling to find a plugin that satisfies all of her requirements. Does anyone know of anything that might do the trick?