From an Amazon marketing point of view, e-Readers should ideally become synonymous with Kindle. Lots of profit there from consumers following the herd and only buying this brand.
Naturally this incurs a dangerous line to walk. I did something a fortnight ago, which would have chilled the blood of any Amazon executive in earshot. I asked my parents for a kindle. Note the small 'k'.
I wasn't necessarily asking for the brand, but for an e-Reader. As soon as the request was granted, I began researching e-Readers in general. Amazon's Kindle was only foremost in those I examined.
If the brand crosses the line into describing a product in general, then it may lose its trademark protection, at least in some countries. Such generic words as aspirin*, kerosene and thermos started life as exclusive brand names. But when people started referring to all willow bark derivative painkillers as Aspirin, then it lost the capital letter and the company behind it lost the right to protect the name from competitiors.
(*It's been pointed out that Aspirin did not lose its trademark protection throughout the world. In fact, Bayer were able to safeguard its brand in 83 countries.)
Another exchange, this time between a friend and I, would have similarly upset Amazon's marketing team.
"Did you get a Kindle for your birthday?" He asked me.
"Yes!" I blithely responded. "I got a Kobo!" Then went on to tell him how wonderful it was reading Jane Eyre in the place where it was written.
You can almost imagine the gods of Amazon screaming out in desperation, "No! You didn't get a Kindle! You got a Kobo!"