With iPhone and iPad, Apple has a habit of keeping last year’s model around when new models are launched. This time, following iPad Air (5th generation), Apple will sell the very aging, non-Retina iPad 2 for $100 less.
Why keep a nearly three-year-old tablet in the iPad line? Because it continues to sell fairly well.
I don’t think so and there’s little evidence of that (Apple doesn’t divulge individual numbers for models). Wouldn’t Apple sell more of the iPad 4?
The older an iPad generation becomes, the better its lower-end configurations sell
That’s probably not true. Common wisdom would dictate that older iPads sell in lower numbers than newer iPads.
The iPad 2 is around because Apple can make them for less money, and they create an opening for customers to migrate up the product line to an iPad mini (same price) or much improved iPad Air for only $100 more.