When Buffett talked about why he invested heavily in Gillette back in the day, the Oracle of Omaha's business moves and logic were incredibly simple: We invested in Gillette because it has held a 100-year dominance in the razor and blade business. Plus, every night, billions of men around the world are growing facial hair, and an even larger number of women are growing leg hair. Although, I try not to think about women’s legs too often at night. Behind the humor lies the cold, hard business logic: high frequency, essential demand, absolute monopoly.