So I have to admit personal blogs don't get much attention and unless your well known it can be difficult to get a strong following. With that being said, I don't really expect many people to read my posts. However, there are different reasons for having one. 

First, I do a good deal of political and economic talk and most of this is done on Facebook. While it is easier and there is more back and forth conversation, you can alienate a lot of people and friends who aren't exactly interested in hearing your opinions or find your constant posts obnoxious. Also, blog writing is a good way to go into deeper detail than you could on Facebook without making it look like your writing a novel. Cultivating your writing skills is another important aspect of it. Going stale on writing is never a good idea, especially if you plan on going onto a professional career. In addition, it's a good way to organize your thoughts and to use as a future reference point. 

Enjoy!