some more history, i think we had the one of the first link networks ever, i started it in 2008, im not aware of any others around that time, but there maybe others here who know better. it used to drive me nuts buying links of dodgey link sellers who sold cack and all were selling non contextual links, back then is when i stopped building apps and started developing in the SEO space, the CMS I use today for management of the links and articles, writers etc. The CMS has become much more advanced over the years. I think without such a thing it would be impossible for most others to get into, hence why when most people sell such services they do it all from behind closed doors. As they wouldn't be able to show you the backends etc, as they are so rough or iffy that it wouldn't inspire confidence. I think this is the biggest hurdle for anyone to over come if they want to build their own. You could try and use wordpress but it would be a nightmare of logins and logouts to manage the content, plus it wouldnt offer any special features dedicated to SEO. For example ours manages the small team who work around it, so that everyone is always on the same page. There is no one asking what do you want me to do now, its all managed.