Many have questioned whether an upsurge in tablets sales would dip into sales of other portable computing devices, especially netbooks. Shedding light on that concern, Best Buy has revealed internal figures suggesting the iPad has cut notebook sales by up to 50%. Much of that is netbooks -- a segment Apple isn't in -- and since Mac sales continue growing, it seems on the surface that many shoppers are opting for the iPad over Windows-based mobile PCs.

Partially validating that estimate, Morgan Stanley has issued a new report showing that notebooks haven't been flying off shelves elsewhere either, and "tablet cannibalization" is at least somewhat responsible. The research firm says that US retail notebook sales fell 4% on-year in August -- a trend that has supposedly carried over to the first weeks of September. The outfit expects that pressure to continue as more vendors launch slate devices.