You do an excellent job as a curator by searching for newer posts. Most only vote for those authors who are very likely to trend.
As for the vote trade, I think that is unhealthy.
But then if someone spends hours on a post but is ignored, it is very discouraging.
So asking for a vote in return of something is very lucrative for the lowly minnow.
Aside from the joy of digging out good content, I also do it because it earns me 100x more curation rewards than voting on trending authors. :)