My idea is something like
"Subscribe and get the chance to won x amount of ink"
Or
"Answer the trivia and get the chance or win an illustration"
Something like what @Larslaustsen is doing on the catmen sorceress.
If the price are illustration we can have volunteers from this event (i volunteer for the illustration because im poor and cant purchase ink)
Its just an idea, we can oromote on other promotion treads too, and social media, so everyone here could get te chance of bein seen