These Sites w/Articles - No Submission/Contact Form

Ok. I see A LOT of these websites that have a ton of articles on them, yet there's no submission form or contact form on them? How are these articles getting on these sites? Perhaps some private blog network, here's just an example of one:

http://www.pmyner.com/category/home-family/pets

My competitors almost solely use those types of sites to get backlinks and I can't figure it out.

Any Ideas?

Because I can write articles like a mofo, how do I go about doing the same?

This guy literally has 80 links from 80 different sites like above, and I see it with a lot of top results.

Yeah, just a simple private blog network.
There are many out there, and on here in the services section.