[amartya916]

If I understand your point correctly, you are referring to the fact that some products by being first-to-market or by popularity start to define a category of products. For example, vacuum cleaners in the UK are mostly called "Hoovers", or say "Coke" represents a cola soft drink etc.

In those cases, people won't buy a product and return it. Although they refer to a vacuum cleaner as a "Hoover", they go in knowing fully well that they are buying a product that does what a "Hoover" does, i.e. pick up dust. Here people didn't go in wanting an iPad-esque product and buying a product in the same category, but rather they mistook it to be the iPad. Pardon me if this seems a little circuitous, having trouble with words today :)