My first reaction was to be angry at the mean, incompetent credit card companies trying to lure my tween into a life of debt. But as often is the case with parenting, and with finances, the story is more complicated than that. As I dug further to find out what happened, I got an education in both how credit card companies work and why I need to teach my kids about Internet marketing.

College students, teens and tweens certainly represent potential piles of profit for a lot of businesses, credit card companies included. The average college student carried $3,173 in credit card debt last year, according to a Sallie Mae report. Firms compete hard to get your kid’s business, using professional youth marketers to locate prospects. These so-called “list aggregators” scour magazine subscription lists, Internet sites, retailer databases and more, in order to find the next generation of college students — and credit-card holders.

It was one of these firms, American Student List, which sent my daughter’s name to Discover and 1st Financial Bank. American Student List says on its website it is the “most trusted name in youth marketing” and promises “the most comprehensive youth data” on teenagers and college students.

But the credit card materials my 12-year-old received clearly stated they were for college students over the age of 18. How could American Student List get that so wrong? I wondered whether my daughter’s actions had something to do with this.

So I asked American Student List how it got my daughter’s name. Sure enough, she had clicked on one of those annoying pop-up ads promising a free gift. That took her to brandsurveypanel.com, a marketing site that sends out “free” gifts to people who sign up for a variety of promotional offers. You have to be 18 to sign up — so my 12-year-old, eyes dazzled by the prospect of a free iPod, obligingly entered a fake birthdate.

American Student List was even able to tell me exactly when she accessed the site: Jan. 4, at 11:50 a.m.

Both credit card companies, Discover and 1st Financial Bank, apologized and immediately removed my daughter’s name from their files. So did American Student List. Wayne Nesje, a vice president with 1st Financial, assured me that if my daughter had actually tried to get a card from the mail solicitation, she never would have been able to.

I do think it ought to take more than just one pop-up ad click to get my daughter on a credit card mailing list. But we as parents also have some real education to do when it comes to online consumer behavior. We worry about sexual predators and inappropriate content on the Internet — understandably so — but I think we miss the fact that our kids’ online travels also make them targets for marketers. Clicking on a pop-up ad or signing up for an email list puts them in the sights of companies hoping to sell them something. And often kids aren't mature enough to understand the strings attached to these deals, or how they might get in over their head financially. So I’m calling this a teachable moment — time to give my kids a lesson in credit, and online responsibilities.