Just a few quick thoughts on Qondio: There are a couple of things that make it stand out from other sites in its niche.
Firstly, you have to pay a five dollar lifetime joining fee. Obviously this would be off-putting to a lot of people. But I suspect that the reason they require this (aside from making a few bob!) is to weed out people who are not serious or who are just going to spam the site with duplicate or shoddy content.
And the site is definitely rigorous about members only submitting original content. The terms and conditions make it very clear that if you do submit stuff you've placed elsewhere they'll just ban you from the site.
So, they're clearly focusing on this particular aspect of SEO. They know that if they only have original stuff there then the whole site will rank a lot better a lot quicker. And those SEO benefits will subsequently trickle down to every member who writes for it.
Also, they know that those submitting their work are doing it primarily for SEO purposes and they definitely want to attract more members on that understanding. The Qondio front page makes a point of saying that it's a great place to build backlinks, which is not something you see on other sites like it.
So, taking these factors into account, does it deliver? Well, I've only submitted one bit of "intel" so far. I just did a backlink check for the site I was linking back to from it and found that that particular bit of content already ranked high on the list. So it does seem that the search engines do regard Qondio quite highly. And their zero tolerance for dupe content policy does seem to be paying off.