Jez
This is what i did when i was doing something of my own which i ended selling and regrading it big time.
make another section on forum and call it Sponsors Advertisement or something like that then what you can do create a sub-forum in Sponsors Advertisement with names of company's that actually are supporting you and give them full access to they section only so that they can post up deals/sales etc or end of year clearance, what this will do is actually promote them and promote the equipment that they have on sale, lets face it i don't go on every web site ie Rhythm or STM or any other shops to see what they have on sale ( we only go if we hear from someone else), however if they had they on section here i am sure ppl will go there and see what is available.
it could look something like this.
Sponsors Advertisement (click to go to that section)
L STM (Click to go to STM section) and under STM you can have they PICTURE LOGO
L Promotion Sales (thread)
L Mid Season Sale (thread)
and so on.
also what you can do is move the forum from center to left side and on the right side you can have LATEST OFFERS FROM OUR SPONSORS that is scrawling up and down or something on those lines.
Just my 5c
i had spare time so see the pic what i mean .
