Sponsorship of the entire calendar. I'll plaster your name all over the shop, basically, in both crass and inventive ways. You'll also get your very own, personalised commemorative bottle-shaped reward, plus that very same vague promise of a round. But this time, I'll double up for last orders.
Actual sponsorship of one of the days, an invite to come round and share that day's calendar treat (or another suitable and relevant bottle-shaped reward posted out if you're not in London or can't make it), plus the usual vague promise as above.