John Gruber had a good observation about the charts published in Quartz (specifically the last one): "Apple has sold more iPads in its first 57 months than they sold iPhones in its first 57 months."
If Apple pumped out over 250 million iPads, a great majority of which is probably still in use, with the usual Android and Windows numbers the whole tablet population must be in the neighborhood of one billion.
I believe the "slower update cycle" explanation, and I'd guess many are waiting for wireless battery charging, nowadays the obviously missing hardware feature.
http://daringfireball.net/linked/2015/04/27/quartz-chartz-ap...
http://qz.com/392202/were-live-charting-apples-second-quarte...
If Apple pumped out over 250 million iPads, a great majority of which is probably still in use, with the usual Android and Windows numbers the whole tablet population must be in the neighborhood of one billion.
I believe the "slower update cycle" explanation, and I'd guess many are waiting for wireless battery charging, nowadays the obviously missing hardware feature.