The curation algorithm strongly favors voting on posts with no payout rather than on posts with payout, especially those exceeding 0.04$.
Why 0.04$? Because even if your goal is to prevent a post from yielding no rewards at all by being rounded down to zero, how likely is a 50% decline within a week?
Downvotes spice it as usual, and considering them, even a 2$ payout does not guarantee rewards for the author.