Before trying to figure out if it is really possible to make extra money through blogs, let us understand what blogs are basically. Blogs are nothing but tiny websites or a part of a larger websites that are often maintained by an individual or a small group of people. A blog might be generic like a diary of events about self or could be specific to a particular field like sports, medicine, insurance etc.
These are potential sources to earn through advertisement, once you make the minimum initial investment and the maintenance along with updates, to ensure good traffic flow to your blog. So, with a greater knowledge of these facts, people have started to come up with innovative ways of presenting their blogs to the targeted online audience and earn their way. There has been many instances where this income has grown to the extent of overtaking their income through full time employment.
You could start a blog for general writing but if you are serious about earning from it, you ought to be having the most appropriate of the content written. Lots of blogs and contents go into the oblivion, within weeks of being created, due to the lack of the necessary maintenance and updates. Your blog can be hosted by blogging services like Blogger, Word Press, etc or you can do it under your own domain name, though you may have to spend a few dollars every year. Once you have set up your blog, you may have to decide on what should be content and its relevance and the traffic it can attract.
Make sure to choose some kicking and live topics for your blog content rather than outdated ones. After you choose an attractive topic and have ensured a regular readership to your blog, then you start letting in advertisements into your blog from Adsense to Affiliates products. This is called monetizing your blog. This answers the primary question that it is indeed possible to make extra money and earn from a blog.
Here again, you have to be careful while you allow the use of ads in your blog. It must be your responsibility to choose ads which are relevant with the content of your blog.