In truth, the way these programs have degenerated in recent years, unless you are able to fly 25,000 miles per year AND make the minimum spend, there is not much point in participating in the AA/UA/DL programs anymore.

The extra money you spend to stay loyal to one of them (versus just buying the cheapest ticket every time) will probably add up to more than the value of any reward.

Southwest might be a better bet, but you'd still need 25 one-way flights to qualify for A-list status, which is a monthly RT home from college and then some. And it would be silly IMO to buy extra, unnecessary round trips at the end of the year given the comparative marginal value of the reward.