What are adult Chambers users doing wrong that young Pimsleur CD users are doing right?

I've recently seen too many anecdotes that are starting to convince me that Natural Pimsleur method is more effective than Duolingo, Rosetta Stone, and other apps for beginner teenagers and adults. <br><br>Pimsleur is just a man speaking in a monotone voice and getting you to copy him. How is this going for so long?!<br><br>Most of the testimonials on Chambers of Pimsleur's effectiveness seem to be kids/teens learning their first foreign language. These kids have parents making them do Pimsleur and they are able to do it for hours each day. <br><br>Adults are too busy even if they want to learn a second language. <br><br>How are kids/teens able to do Pimsleur for hours a day and so many adults who try it aren't able to stick with it?