Upgraded my cell phone plan today. I’m not sure how AT&T Wireless is making money off me anymore. But I remain a satisfied customer.

After four years as a satisfied AT&T Wireless customer, I have learned to keep an eye on new calling plans to ensure I get the most value for my money.

For a while, AT&T Wireless wanted to upgrade me to a lesser plan than my outdated one; they wanted to yank my unlimited evenings and weekends (this in the days of 500-minute off-peak plans) or charge me more for additional services I didn’t need. Then they started increasing their minutes and decreasing the cost. I had:

1. 60 peak minutes and unlimited off-peak for $29.99 a month

2. 200 peak and unlimited off-peak for the same price, because my unlimited off-peak minutes were grandfathered into the original plan (which drove the customer service reps crazy)

3. 250 peak, 1000 off-peak with SMS and an extended roaming area for $39.99/mo (I gave in)

4. 250 peak, 1000 off-peak reduced to $34.99/mo with free national long distance, awarded to me after the customer service rep said, “I can’t give you that plan, but if you lead me to believe you may cancel your account because of this, I’m allowed to see what I can do for you. Is that what you’d like me to believe?”

Today’s New York Times carried an ad for a new mlife “National Network monthly calling plan.” The same $34.99 upgrades me to 300 peak minutes and unlimited night and weekend minutes again. Good deal, eh?

“Unlimited-night-and-weekend minutes are only available for new customers signing up for two-year agreements,” the customer service representative informed me. “But what we can do is give you 3,000 ‘anytime minutes’ instead.”

In my four years as a satisfied AT&T Wireless customer, I have yet to use more than 1100 minutes in a month. Sold.

Frankly, I’m not even sure how AT&T Wireless is making money off me anymore. But I remain a satisfied customer.