Publishing content on a blog can be a huge commitment, in terms of the effort and time you have to spend. Naturally, a question has to come up, as to what could possibly motivate you to take this path of publishing content on a blog.
Now, the first thing that may ultimately motivate you to publish content on a blog is the desire to make money out of that content. That can be through something like pay per click advertising, through affiliate marketing or through some other commercial program. So, like many others before you, you decide to publish the content on a blog, to see if you can make money out of it.
The second thing that may ultimately motivate you to publish content on a blog is the desire to push a certain idea. You may, for instance, be inclined to do something about inmate treatment in the various correctional facilities in the country, and that motivates you to create a blog on the same. You may also be under the motivation to push some other sort of positive idea, to agitate about something and so on. Social media has turned out to be a key avenue for social mobilization: hence this idea.