Re: How big?
ShelLuser - About 2 million units a month in the summer for iPad. Probably 2.5 million per month or 3 this quarter. With profits about $280 per unit including accessories and whatnot, about $700M per month in net profits for Apple. It's not bad for a new product, but it's no iPhone.
Android's probably approaching those sell-through numbers now, but it will never be reported because it's mostly cheap knock-on tablets sold into parts of the world that don't have our compulsive counting fetish, made by people who change their names as often as they buy shoes. Margins are low presumably, but not so low as cheap consumer laptops.
IDC says that for 2011 tablet sales will be 15% the size of the PC market. But tablets didn't really start hitting their stride until summer. Maybe next year 25-30%. Year-on-year growth is difficult to gauge when it's ramping at this scale.
Meanwhile, PC sales are flat.
Nobody's going to buy Windows on a tablet or a phone. Look at your Windows desktop PC. Now look at an iPhone, iPad, Android phone or tablet. Which is instant on, fluidly responsive, and a joy to use? Which one is "cool?" That's why. We're going mobile and Microsoft isn't coming with us.