US 13-to-17-year-olds send or receive "an average of 3,146 texts a month each" – an average of 10 text messages an hour for every hour they're not either sleeping or in school, MarketingVox.com reports, citing the latest Nielsen figures. For 9-to-12-year-olds, the average is 1,146 texts a month or four an hour. The teen figure was for third quarter 2009, the tween one for the fourth quarter. Compare those youth numbers to the average number of monthly texts for all mobile users: 500. As for methodology, in its blog post about these findings, Nielsen reports that it "analyzes more than 40,000 mobile bills every month to determine what consumers actually are spending their money on."