At the end of the day it's just not worth the time and money to set up protection schemes for Indie devs, that's why you'll almost never see them. For most it's not a big deal, and people stealing your games and it's code/assets is just apart of the business sadly - but that certainly hasn't made websites like gog.com (drm free) suffer.
So don't worry about it so much, and just make a kickass game that people are excited to purchase. (A free demo can help in that regards too!)