Trendcentral has released the latest issue of its Tween Intelligence Report intended to provide an insightful glimpse into the lives of 7-to-13-year-olds. One of the most important lessons learned by Trendcentral is that the tween market is rather difficult to peg down since they're always changing. Here are some interesting statistics:

• 88 percent of tweens have been online in the past month
• 56 percent of tweens look to friends' purchasing habits when deciding what they want to buy
• If they had to choose between being smart or popular, a majority of tweens said they'd rather be smart (72 percent) than popular (28 percent)
• Tweens' favorite store is Wal-Mart