Well, we held a poll on that very subject, namely, how often you want a poll! The answers were pretty comprehensive.
Weekly: 10/27 (37%)
Monthly: 1/27 (3%)
Randomly: 5/27 (18%)
Never Again: 11/27 (40%)
So it seems you guys don't like polls! This makes me sad.
We'll probably still have the occasional poll, but only if we want to poll something important.