I'm very new to the platform. I've read a lot so far, but there are some points that I still don't understand on Steemit :

Upvote yourself (Story or Comments)

Why ? When you post something, it has to be something you want to promote. Otherwise, you'd never posted it!

Upvote loop

If I post a thousand times and I upvote them all. I really earn money every time?

Curation system

If I can be rewarded when I upvote a new post that will become popular. Why I shouldn't reward each stories in the "New" section ? (https://steemit.com/created)

https://img1.steemit.com/0x0/https://i.imgsafe.org/92127d604b.png

I've been looking for post explaining that but without success. If you have a link that answers my questions, feel free to post !

EDIT :

For those who share the same issue as me, I get the answer.

This is all about 'voting power'. This voting power is not displayed in Steemit but there is some website that give you more data about your account. You can find your own on https://steemdb.com/@username or https://steemd.com/@username

Upvote yourself : When you don't want to spend your voting power on your own post (making better use while voting on other).
Upvote loop : The voting power decreases at each vote. So you can't do that.
Curation system : Because of the voting power decreasing overtime. If you spend your power on crap this will not be usefull. So you have to vote carefully.