One big challenge for online game companies is how to make money from children who play lots of games online but don’t have any cash. At the LOGIN Conference in Seattle, panelists talked about some of the strategies that online gaming companies are adopting. Warning: Easily outraged parents should not read on.

—Mobile payments: While kids might not have credit cards, they are likely to have cell phones, often paid for by their parents. So, one option is to introduce a payment method that lets gamers pay for virtual goods simply by entering cell-phone numbers. David Marcus (pictured, right), the founder of mobile payment company Zong, said it’s an attractive option not only to get dollars from kids but from some adults too. “Let’s imagine you’re in a casual game where you can buy a virtual gift. You want to buy a two dollar (item). With a typical credit-card form, half way through you’re like, what are you doing?” he said. People are about 10 times more likely to complete a purchase if they only have to enter their phone numbers, he said.