You may be reading successful stories over the net about successful bloggers earning high income from blogging revenues. Has this stories prompted you to leave your current job? Will you go for full-time blogging?
I asked this question to myself and I answered it in one of my post saying - if blogging will give me 3 times my full time job income, I will consider going full-time blogger. But for some people, perhaps they see fullfillment in their present job, blogging for them is just a part-time job regardless of the revenue they will derive from it.
But if you consider doing it full time, my advise is that - do not leave your present job just because you know someone making a good living by blogging. Test the water first. Try to make your blog successful first, that's the beauty about blogging. You can make a successful blog doing it part-time. Second, see if blogging work is really for you. Blogging like other jobs requires some set of personality.
At this point, I'd like to bring you to one of the post made by Darren. The Monkey Bar Blogging post where he shared his transistion from part-time to full-time blogger, also provide you some reality check about blogging as a profession. With Darren post, I hope I provided some cautionary and realistic advice for people who want to blog for a living.