I can get compulsive about both, but I'm definitely on the "user" side, having earned about 1.5 million lifetime miles and spent 1.3 million of them.

Like a few others here, my funds are very tight. I'm too much of a mileage miser to use awards for anything but free travel. I'll typically do short domestic or Europe trips to earn miles and longer trips to "cheap" countries (Southeast Asia is a favorite) for redemptions.

A big part of the game is piecing together elaborate bookings, using the Internet as an aid.

You can do it for both paid tickets and award tickets. On award tickets, I really like to use the stopover and open-jaw rules to best advantage (why see one place when you can see 2 or more?)

It's also neat to dig through the partner and other awards and frame the possibilities. I especially like the more out-of-the-way places; a recent sidetrip for an Asia trip went Manila-Marshall Islands-Guam-Yap-Manila. Great trip, and for only 20,000 miles (vs. a $1,000 paid ticket).

It takes way too much time to book it all and get it to work, so there must be something habit-forming about that. I think it's important to use the miles, though.