Looking at sales as an indicator of the success of a product is warped and silly. The fact that it is considered the right way is a shining example of the fundamentally flawed nature of our capitalist system.
Up until last year when he moved out, I continued to use my dad's first generation iPad while he used his new mini. The first generation iPad worked great, I used it all the time. I saw no reason to go and purchase one of the newer ones for myself other than the fact that I couldn't install iOS 7 on it. The software pushed obsolescence, not the hardware. My dad kept it when he moved out because it was still a great device.
A more accurate title would be "No one knows of any reason to buy the new generation iPads because their older ones are working just fine"
Up until last year when he moved out, I continued to use my dad's first generation iPad while he used his new mini. The first generation iPad worked great, I used it all the time. I saw no reason to go and purchase one of the newer ones for myself other than the fact that I couldn't install iOS 7 on it. The software pushed obsolescence, not the hardware. My dad kept it when he moved out because it was still a great device.
A more accurate title would be "No one knows of any reason to buy the new generation iPads because their older ones are working just fine"