Thats lovely, meanwhile the sales of the iPad are sinking like a stone.
Only because sales of the iPad were so high to begin with. We are talking about a brand new product market, so the first few years of sales will paint a distorted picture as everybody who wants one will get one.
After that, we are now in the replacement cycle. I have been getting a new iPad every 2 years as I use it for work and value the added specs and functionality. Normal consumers who use it primarily for consumption would likely use it till it dies before upgrading, which can be 4-5 years in between.
What we are seeing is simply the sales of iPads tending towards the new normal. I don't think there is anything to be alarmed about.