Customer characteristics used by cellular manufacturers in the past would have consisted of income (because not everyone could afford a cell phone then), profession (not everyone needed a cell phone), phones were bigger because bigger was expected to be "studier," they were very simple (didn't have all the bells and whistles, games, cameras, etc) they were just phones used for communication.
Today Nokia uses a plethora of characteristics and segmentation variables to identify the target market(s) for their products. Many of the segmentation variables that Nokia uses are mentioned above as the "six segments" that Nokia has identified and defined as possible target markets. These "six segments" include, Basic, Expression, Classic, Fashion, Premium, and Communicator, and are further defined in the article and the fourth paragraph of this article. Other customer characteristics would still include income (you don't want to market a product where it can't be afforded), profession, culture/geographic location (different phones are available in different parts of the world - many more technological phones aren't available here because Americans have a reputation of being careless and breaking things), etc.
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