Marketshare IS important for consumer products, its an indication of popularity... which is important for 3rd party development.
Marketshare is a poor approximation of success. Market
activity is a much more accurate indicator.
For instance in terms of attracting 3rd party applications, you need to evaluate the size of the market. And that means you have to consider how many people actually go out and buy apps. Nokia sold 20M smartphones. How many of these 20M users actually buy apps?
When looking at Apple there are two unusual factors.
iPod Touch customers, increase the market size for apps by a factor of two or so. iPod Touch does not appear in the Smartphone market share figures, but please do not disregard it. Software developers see the iPhone platform as twice as large as these smartphone figures suggest.
And there is a second factor. Apple customers actually go out and buy apps. Whereas Nokia customers don't go to the Nokia Ovi store. Android, Pre and Blackberry application sales have all been much weaker than Apple.
Example: Games which have done $250,000 on iPhone have sold 500 units on Android.
So looking at the market from the point-of-view of a third party developer,
you should take into account these units sales and then MULTIPLY the figures by these attach-rate factors. That will give you a much more accurate view of the various markets.
Once you do that, you realise that 1 x iPod touch is a bigger market than 10 x 5880 "music-phone" sales.
Marketshare is only important if vendors can translate it into revenue generating activity. And in the mobile space, Apple seems unique in its ability to do that.
C.