It's not strictly about being a bad customer of the airlines... You can get free flights by being bad customers of other businesses offering airline miles (like

It's not strictly about being a bad customer of the airlines... You can get free flights by being bad customers of other businesses offering airline miles (like credit cards) or by defrauding taxpayers (the well-known "buy dollar coins from the Mint" scam). This might even be profitable for the airlines. Sometimes.