The reasons for failure are sometimes obvious:

1. People (mostly from poor countries - not trying to be racist here) think they can make big money by just posting anything --> a lot of really poor posts!

2. "Vore for Vote" post - or even worse: You post an long article with 1000+words and pictures --> 30 seconds after publishing "Great post, thx for sharing - please upvote and follow me". I have to lol so hard when I see something like that. I also share links of my posts f.e.. BUT only in posts related to mine and after I have read the post and understood it. And I go into detail and ask things I really want to know. I just share with people who I think post similar stuff than me.

Those are the two main errors I see. But there are many more ;)