In the marketing context, this can be interpreted as being unable to see "the big picture" - such as what's going on in the wider market-place. Theodore Levitt, who first used the phrase, gave as an example the situation of the US railroad companies who saw themselves as being in the railroad business, rather than the transport business; as other forms of transport (such as airlines) developed, the railroad companies missed out because of this (marketing) myopia.
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