Motivation is the biggest factor that can lead a person to success in any endeavor he or she may undertake. Motivation is such a thing that can give you powers that you never knew you possessed. You can climb a cliff or swim across the ocean if you have the right motivation. These are not my words but the words of the most famous motivational speakers and writers around the world.
So, the same thing must apply in the case of success in blogging too. But motivation can mean different things to different people. Some one can be motivated to gain even a little attention whereas some one else might want to reach the top of name and fame. So, you should first be decided upon what is that motivates you to blog in the first place.