That is exactly my point. Install Base and Market Share are completely different concepts. Market share is a simple measure of this year's sales. Install base

That is exactly my point. Install Base and Market Share are completely different concepts. Market share is a simple measure of this year's sales. Install base is only relevant to things which are used over a period of years. Coke and Pepsi have market share but not an install base. Linux has an install base, but market share isn't a relevant metric.