I'm pretty sure that every single vote delivers some reward, for example; these are the votes on your article about BBQ meat 2 days ago:
even with low percentages votes, these votes generally weigh in. So it does pay, albeit that in some cases, some payouts are rounded down to 0. But in general, it pays off for both authors and voters. But yes, you are right, the pay-off is so minimal, maybe not doing it and simply using 100% upvotes is more effective. (Well, that's usually what I do...)
By the time you get to those last few low people - the money is gone. Compare your votes to your payouts and see how many of your votes are giving you rewards. I personally would like to be rewarded for 100% of my voting effort. i want to get to the top of the list - not hang on at the bottom forever.
Downvoting a post can decrease pending rewards and make it less visible. Common reasons:
Submit
If you find a post that's older than 30 minutes and you are the first to vote. Then you resteem it and other votes are coming in, you will see massive curation rewards.
Downvoting a post can decrease pending rewards and make it less visible. Common reasons:
Submit
FAQ Steemit
How is the reward pool split between authors and curators?
Up to 25% of a post's payout is awarded to curators (the people who upvoted the post) as a reward for discovering the content. The other 75% is awarded to the author. If curators vote for a post within the first 30 minutes of it being created, a portion of their curation reward is added to the author payout. This portion is linear to the age of the post between 0 and 30 minutes. Therefore upvoting at 15 minutes old will donate half of your potential curation reward to the author.
Downvoting a post can decrease pending rewards and make it less visible. Common reasons:
Submit