According to proponents of this myth, a vendor’s market share numbers speak for themselves as a critically important factor in selecting a technology product or platform. They're wrong, here's why.
Why the Myth was Woven
Market share is often used in spreading FUD. It has been used against Apple's Macintosh since its introduction over twenty years ago. Professional nay-sayers have long insisted that the Mac's limited market share would prevent it from benefiting from the hardware economies of scale that were driving PCs cheaper, as well as the widespread software development forces that were introducing a wide range of diverse PC applications.
Clearly, this inconsistent use of facts to suit their purposes indicates something's wrong with the simple conclusions drawn from market share numbers. It also calls into question the credibility of those who use market share to make broad, sweeping generalizations.
Like most myths, there are elements of truth buried within the layers of wrong ideas. Let's pull apart what market share is, how it can be misinterpreted, and how numbers can easily be skewed to present false information.
Unraveled with Extreme Prejudice
Myth in the PC Market: 1980-1996
The market that Apple had a fifteen percent share of in 1980 was nothing like today's market. Only the flaming edge of early adopters were even buying computers, and mostly as a novelty. Still, there were far more than five major makers of computers, so Apple's share was very significant in comparison to its competitors.
Fifteen years later, Apple was at just under 5% of the market. According to the industry wags, this was because Apple had failed to broadly license their operating system to other vendors. Instead, Microsoft had blossomed as the provider of DOS software for the dominant IBM PC compatible market, and had just released a program for DOS that copied much of the look and feel of Apple's Macintosh.
The problems solved by the Mac's innovative new graphic interface were of obvious value to artists and designers, but less so to users who were simply entering data, and of little benefit at all to office drone workers who were simply connecting to an existing mainframe as a dumb terminal client.
A low cost PC terminal with minimal functionality and an obtuse but simplistic text interface was a perfect match for the millions of office workers in cubes. Apple could have dropped their premium, innovative product to build PCs, but that would have thrown away Apple's clear edge in profitability and would have forced them to compete in a market only concerned with shaving the price of commodity hardware.
Further, DOS PCs had low operating requirements, and could not have magically run a fully graphic operating system without significant upgrades. Who would this Mac software appeal to? Business users who didn't want to invest in Macs wouldn't have been much more likely to adopt Mac software if it would have similarly required them to beef up all their office workers' machines to do so.
Myth in the PC Market: 1996-2006
In the ten years following Windows 95's release, the Mac market share appeared to wilt from 5% to 2%, but those numbers similarly betray reality without considering some context. Apple is quite obviously doing better today, and has a brighter outlook for the future than they had in 1996, when they were at their lowest point of operational, technical, and strategic failure ever. How is it possible they now have less than half of their 1996 market share?
Prior to 1996, the PC market had already grown to include many market segments that had little to do with Apple, as noted above. So while their overall share of the PC market is useful in comparing Apple's performance to IBM, Dell, or Compaq, it is not material in considering the value or utility of Apple's product or platform.
If Apple had tried to build Windows PCs, or to compete against Windows as an operating system on PC hardware, those overall PC market share numbers would be very relevant, but Apple didn't. Here's why.