Well if you have the money to invest, then powering up in SP is always a good idea since it will help you to grow faster. Still not everybody has these opportunities (including myself), and you can also build up your brand organically without investments even though it will take longer. I didn't power up anything and earned ~27,000 Steem by blogging in 18 months. That's more than a regular annual salary on my island so it means a lot to me. But you also need to know that I have been working daily on this platform since the very first day.

The most important part is: time :-)