This is just a thought, don't shoot me down...
Would the supporters' club be more appealing if the prizes were changed regularly and/or bit more universally desirable?
I won once, years ago, and never actually bought anything with my £100 of spud reloading money because I didn't reload and couldn't decide on anything I really wanted from there

Likewise, I don't really want/need a new set of limilus sticks, if I won them I'd end up giving them away or asking
@sikamalc to re-draw.
I still support because I think I've benefited plenty from the forum and it's nice to give a bit back. However, if you want to entice people via the prize draw it needs to be prizes people definitely want.
The obvious, though dull, option being vouchers for a decent online seller with a wide product offering...