At least for me, I have two different voting style:

- Yeah, this is pretty cool. Upvote!

- I've got to save this for later when I can really read it

PostgreSQL stuff tends to be pretty reliably good, and usually with an educational bent. So I'll tend to use the upvote as a bookmark to go back to later.

I gotta say, I don't really like slides, but I've yet to be disappointed by a PostgreSQL post. And usually, a high vote/comment ratio is a nice indicator of quality.

EDIT: formatting