Shipped != sold. Atari shipped 5 million copies of ET for their Atari 2600. Guess where nearly every copy is at now?
You do realize that reviewers consider the iPhone 4 and 4S to be fragile because of the glass front and back. I dropped (well, my toddler) my iPhone 3GS numerous times against concrete and the case suffered numerous scuffs, but still intact. If my iPhone 4S suffered the same treatment, it would likely be shattered in under week. There is a reason the industrial design did not catch on with the rest of the cell phone industry.
I've dropped mine numerous times and it has been more durable than my 3GS.
If you're worried, get a case.