Should the time devoted to development be proportional to the market share?

Should the time spent on developing a new software product be proportional to the market share of the platform? For example, if Android is 50% of the market share and Apple is 25%, then for every 2 hours spent developing an Android app, you should only spend 1 hour on iOS.

Is this the best best strategy money-wise for a startup that needs to develop similar software for multiple platforms? In which cases would you go against this seemingly common sense strategy?

Another tricky place to allocate resources is in website development. There are still large chunks of people using Internet Explorer 6, 7, and 8. Even though IE6 has the lowest market share, it's the most difficult to program for. So allocating less time for IE6 doesn't always produce the best website in IE6. Although, others argue that since IE6's market share is so low, it doesn't matter if you don't have time to put all the fancy features in it.

Kind of, if your own market mirrors the overall stats then it would make sense to focus on the things that will give you the highest return for your investment ...

BUT if your targeting business users with a strong .NET team then your cheapest and best return is is probably WP7 first followed by Android running Moonlight second.

OR if your in Australia then iPhone has a much higher share of the market at the moment, so you might target it first for a general consumer app but its loosing ground ...

Overall... there is no "one size fits all" answer, its pick the right tool for the job and listen to YOUR market and be directed by the trends emerging in that market rather than the state of play as of the last survey results.

Market share/Competitors is more appropriate probably, as a measure of what share of the market you can get. Also, take note that on some platforms users are more willing to spend money on software then on others.