A blog needs to be monetized to generate revenue. It should be a successful blog with a growing base of subscribers to keep generating more revenue. Only then would you have a profitable blog. Any blog can be monetized but there may be no revenue. Any blog can have some revenue but only consistent and sustainable revenue over a period of time will ensure profit. The fact that anyone can start a blog with little or no capital, the availability of a plethora of free tools, the ease with which one can get started and equal access to the audience ensures only the best would win. The competition has never been this stiff.