What brands have suffered enormous collapses in market share?

One example is drawn from the US market for artificial sweeteners. As this graph illustrates, Equal (aspartame) when from market share leader to a much inferior #2 or #3 position. read more

This isn't the case. Alpha Natural Resources has been suffering since the U.S. started getting mild winters driving down heating costs. Many households have also switched to natural gas for heating. This explains why the company suffered a record $677 million in losses in 2011 a trend which is expected to continue. read more

Even more important, Apple now has an opportunity to take market share right now, Cramer said. The Samsung Galaxy was the only high-end smartphone that ever came close to the iPhone. Cramer believes that a significant amount of Samsung users will switch to Apple. read more