There are various ways to make sure, you can blog to the bank.
Blogging to the Bank seems to be new mantra in the e-world.
Let me try to give all some inputs. The objective is not to make money, but to make it on the fly doing your normal stuff.
Dont forget Google adsense or Adbrite. Few cents a day (or a click) is worth hundreds of dollars in a year. All in your pass time.