Check out the graph below. Amazon has sold so many KFs (and increased the number of tablets in use) that the Samsung Galaxy Tab's share shrink from a dominant 63% to only 36%.
Here is a different way to look at it. The KF not only outsold the Galaxy Tab, in 2 months Amazon sold more Kindle Fires than the total number of Galaxy Tab users. Those rumors of 5 million KF sold lst year don't seem so improbable, do they?
But it's also important to note that the Galaxy Tab also saw a serious jump in activity. Flurry reported that they tracked a 50% increase in apps being run on the Galaxy Tab. Clearly the market as a whole got a lot bigger over the past couple months.
BTW, these stats don't reflect how many tablets are in use. No, they show what percentage of apps are opened on which tablet. That's not quite the same thing, but it is significant in its own right. The pie charts above reflect the intensity of the use. People who open 3 times as many apps re counted 3 times, for example. That means there are either a lot of KF in use or some being heavily used. Either way, that's a big deal.