If you mean a poll for dream scenes, I hope you'll reconsider and make it available for the $10 tier. I see no supporters at $15 level and just one at $50, so it's just that person's decision.
Subscribestar doesn't credit pledges already made, so if I wanted to move to the $15 tier, I would have to spend $25 this month. If I wanted to spend that much, I'd consider the $50 tier...
I don't think I made that suggestion, but here's a thought: Make the poll available separately to $5, $10, $15 and $50 levels. Those at a higher level of support can vote multiple times and you can multiply the results on each poll by as much as you like (so a vote from a $5 supporter counts for one vote, a vote from a $10 supporter counts for two votes (one at each tier), a vote from a $15 dollar supporter counts for a total of five votes (one per $5 and $10 tiers, but three at $15 tier), etc.). I don't know if Subscribestar lets you attach weights to votes based on support level, but that would let you automate the process.