Before answering this question let’s consider why do people blog? Blogging initially started among the teenagers who choose Internet to let their thinking or frustration out. But the advancement of blogging from then to now has made it an excellent platform for communicating to different people from the same field. It allows you to share your thoughts and ideas regarding a particular topic.

Bloggers blogging for SEO want to rank higher on the search engine rankings page. And so have to write articles which can generate huge traffic and better ranking for them. In this race many times it happens that the article might open up many trade secrets and even suggest links to some of the websites which the blogger finds useful for search engine optimisation.
 
For example if a blogger mentions a link to a site selling links on the blog. This will definitely help the blogger have increased traffic for a short period of time. But on the other end it will make difficult the job of other SEO professionals as the link sources will amend the loop holes or search engines will devalue the links from that site. For the site actually selling links it will be a loss of credibility, business, ranking and competitive edge.
 
SEO company opines that instead of bringing such link sources into the open it is much better to keep them to yourself and use them to optimize your or client’s website. If you disclose such source in your blogging you will definitely have some extra links but then think will those extra links benefit you more than the higher rank? Is your blog giving you that much return that you can decide to expose a valuable source?

It is not the intention of the blogger to expose anyone, what is done is just to have more traffic to the blog. Still the point put forward here is worth giving a thought Is blogging on SEO really worth?