About four years ago I made the transition from being a casual earner of frequent flier miles to becoming a serious mileage junkie. How serious am I? I attend conferences devoted to the subject and make a nice living writing about loyalty travel programs and credit cards. But having earned millions of points and miles through some ingenious methods, I reached an inescapable conclusion that will sound very familiar to personal finance enthusiasts: Spending points and miles wisely is at least as important as finding ways to earn them.