The BlackBerry’s downfall is almost as crazy as Android’s rise

The latest comScore U.S. smartphone subscriber data shows Google Android continuing its impressive market share growth, with Apple growing more modestly.

But look at RIM. It’s falling to the earth. Just a year ago, more than 40% of U.S. smartphones were BlackBerry devices. Now it’s less than 25% of the market, according to comScore. And despite the overall smartphone market’s incredibly fast growth — still only one-third of U.S. mobile subscribers have smartphones — RIM is actually shrinking in absolute user numbers in the U.S.

At Business Insider, Jay Yarow posted this chart earlier this week. Look at Android’s rise and RIM’s decline. The angles are impressively steep.

What does this tell us? In mobile, no lead is safe. The market changes unbelievably fast.

Thanks to two-year contracts and relatively low costs of switching, today’s winner can be tomorrow’s loser. That’s why Android has been able to grow so rapidly. And that’s also how Android could shrink rapidly if it loses favor among smartphone makers and carriers (Google’s real customers).

Now the question is: How high can Android’s share get? It’s already approaching 40%. I don’t think it will get higher than 60% in the next year, but we’ll see. Microsoft hasn’t been putting up much of a fight. Will Apple’s new iPhones?