I'm not sure. Steem makes it clear that early upvoters will be more highly rewarded, however I don't have any data on how that algorithm actually works. But I definitely see users upvoting articles in less time than it could possibly take to read them. So clearly some users are just guessing at what might be popular by the title, hoping to get lucky.

If only a few users are doing this relatively to the number of posts, I don't expect the effect to be substantive. But if lots of people start doing this, then we'll see even more outliers reaching the upper echelons of viewership and rewards.