Why was Apple's prediction on iPads so wrong?

Apple has announced it is selling far more iPads than it expected and is delaying the worldwide launch by a month.

I am seeing this problem in US too. There are lines in stores (when I went back to buy a third iPad I had to wait in line). The demand is nuts for iPads.

So why did Apple guess its prediction so wrong? Several reasons:

1. They didn’t realize just how many apps would ship on day one and how good the quality of those apps would be.
2. Even the app developers never had their hands on iPads (I talked with several developers, even at “hot” companies like Evernote, while waiting in line, and they had to develop their apps without even seeing an iPad) so the marketplace couldn’t tell them before it shipped just how hot this would be.
3. The focus groups that Apple talked with didn’t hype it up enough with the people studying the groups. This is because they, themselves, didn’t have the apps (the iPad without apps is pretty lame, actually).
4. They didn’t realize how fast skeptics would be convinced. I’ve seen this myself. My son was very skeptical before it came out, saying he didn’t want one. The minute he put his hands on it he started changing his mind and within five minutes of using it said “I was wrong.”

This is one of those dangers that Apple has: predicting demand is really tough when your market really can’t see the complete product before it ships.

On the other hand, this is a very positive sign for Apple. It means that the iPad is moving outside of the “Apple faithful” very quickly, which I have also observed in the stores. The people I met buying iPads a few days later from the opening were quite different than those of us waiting in line.

Apple has a runaway hit. Bummer for those of you waiting for yours.

UPDATE: on the other hand, lots of people are skeptical, including ZDNet.