If a certain system can be used to trick children into spending thousands of dollars, then it's probably not a very ethical system.
I won't stand here and tell you that microtransactions are the devil. I won't even call them a necessary evil. "Evil" is too strong a word. Cliff Bleszinski did a good job of defending them here yesterday. But the freemium model is still a deeply flawed system, as evidenced by the five-year-old who (more or less accidentally) spent $2,500 of his parents' money in the free-to-play game Zombies vs Ninja this week. He's not the only one, either—there are so many similar cases that this week Apple had to settle a class-action suit brought by distraught and disgruntled parents who felt their kids had been exploited.
(Apple did so by doling out $5 iTunes credits, which is a little like saying, "Sorry the apps in our store exploited your children for money, but here, go buy some more apps." That's besides the point, though.)
Are lax parents who give their kids their iTunes passwords to blame? I don't think so.
Take the case of a friend of mine. When he was younger (think high school freshman) his impulse control wasn't quite what it is today. As a result he wound up charging hundreds of dollars to his parents' credit card in one free-to-play game or another. You'd think a 14-year-old could be trusted with that sort of power—I carried around a credit card for emergencies at that age—and at that point you can't plead ignorance. There are typically no refunds for microtransactions, and his parents had to swallow that bill.
What I'm saying is that certain games are designed in a way that I consider to be exploitative. They draw you in, and before you know it you've amassed a massive bill full of just-one-more transactions.
My girlfriend is fixated on Candy Crush Saga, along with many, many other people. It's a match-three game like Bejeweled with varying goals that change from level to level. I see no value in it. She swears that once you get to around the 35th puzzle (in the iOS version at least), you've pretty much got to start spending money on it. It even pulls a trick where it pretends to give you a power-up, but asks to charge you when you try to use it. At that point she quit playing, but when I humored her with a $10 iTunes gift card, she went right back to it and hasn't stopped since. Wikipedia defines "problem gambling" as "an urge to continuously gamble despite harmful negative consequences or a desire to stop." She hasn't experienced any "negative consequences" as a result of playing Candy Crush, but I know for a fact that not everyone has as much self-control as she does. In what way are these games any different from gambling? Only that unlike gambling, freemium games are available to (and often created for and marketed to) kids.
At its most abusive, the freemium system is designed to exploit people with certain traits, like a lack of self-control. Children exhibit those traits the most, so of course they'll fall for it hard when given the opportunity. And judging by the fact that Zombies vs Ninja appears to be little more than another uninspired imitator attempting to ride the success of Plants vs. Zombies, I'd hazard that its Asia-based developers (their website says the company's address is "Taiwan,Beijing,China") Bakumen, Inc. aren't too worried about taking advantage of people.
I reached out to Bakumen directly for a comment on this subject, but I haven't heard back yet.
Of course, it's ultimately parents' job to police the technology they let their kids use. You can even argue that blaming app-makers for unwanted spending sprees is like blaming game developers for making violent games that somehow fall into the hands of children. Shouldn't we leave poor app creators alone? All they've done is create a system meant for adults to use at their own discretion. It's not their fault if kids get ahold of it.
But that doesn't account for the reasoning-aged players who do serious harm to themselves and their families by being sucked into the free-to-play spiral, or even for the presence of microtransactions in kids' games at all.
The "old" game design model rewarded skilled players with progression; free-to-play games with abusive microtransactions replace the time investment required to develop skill in traditional games with a simple monetary value. The problem isn't the kids, or even their too-lax parents; it's the designers perpetrating this system.
I know if I had a kid or two and the same had happened to me, a $5 iTunes credit wouldn't cut it. Of course, I wouldn't give my kids the password to my App Store account either, but hey. Not everyone knows better.