After they buy a smartphone or tablet, most people buy extras such as cases, apps and so on.
For you, roughly how much are these "extras" as a percentage of the orginal cost of the phone or tablet?
For my work iPhone, I've just bought an armband from eBay for < $10 and for my work iPad, I've just bought a Geckogear case for $5. The extras % in my case would be around 1% each to date (if I had paid for the phone and tablet).