Rajesh Lalwani makes some pertinent points in his post on Making Money via blogs. Lots of Indian blogger examples. Even yours truly is mentioned 
However, most people tend to simply associate making money via blogs to advertising. From where I look at it though, significant or even reasonable amounts of money from writing a blog are for a privileged few who dedicate a considerable amount of time & energy to writing their blogs and cover strong niche/s.
Not all bloggers (or those who write blogs along) are equal…but money can come in many different ways. Also let’s not forget that for ‘many’ earning money may just be a byproduct, or not even a consideration – showcasing thought leadership, seeding & engaging a community, or plain expression might be the simple motives.
