Data published by comScore shows that Amazon's Kindle Fire has emerged as the dominant Android-based tablet. At the end of February, the Kindle Fire accounted for 54 percent of all Android tablets. The next most popular Android tablet product line is Samsung's Galaxy Tab family, which dropped from 23 percent of Android tablets in December to 15 percent in February.

The success of the Fire is no surprise to those paying attention to the tablet market—as we wrote last year, there is healthy demand for a low-cost iPad alternative. Amazon can afford to offer the hardware at a lower price than its rivals because it can make up the difference in content sales. The key factors driving sales of the Fire are likely its low price point, the strength of the Kindle brand, and the breadth of the Amazon content ecosystem.

The rising prominence of the Kindle Fire will have significant implications for the Android tablet market. Amazon is using its own application store and a fork of the Android operating system that is based on version 2.3. As Amazon continues to advance the software in its own direction, it could reduce Google’s control over the Android tablet software ecosystem.

Third-party application developers who are building software for Android tablets obviously have a big incentive to ensure that their applications are compatible with Amazon’s popular Kindle Fire. But in order to make an application compatible with the Kindle Fire, it can’t be developed using APIs that are exclusive to Ice Cream Sandwich (the latest version of Google’s operating system).

It’s not clear yet if Amazon intends to update its fork of the operating system to bring it into alignment with Android 4. Amazon’s changes to the operating system are said to be much deeper than the kind of cosmetic changes that handset manufacturers typically make to differentiate their products. As Amazon’s flavor of the platform continues to diverge, application developers will likely follow in order to reach the device’s audience.

If Google wants to keep its own variant of Android relevant on tablets, the search giant will need products that are capable of competing with the Kindle Fire. Google is reportedly planning to launch its own low-cost Nexus tablet, possibly this year. Such a device would be aimed squarely at competing with the Kindle Fire rather than more expensive devices. Google has recently been working to strengthen its own content ecosystem and streamline its various media stores. It's an effort that could help it pursue the same model as Amazon, where content sales are used to subsidize the price of the hardware.

It’s worth noting that other major Android manufacturers are starting to enter the budget tablet market. Samsung recently launched the Galaxy Tab 2 7.0, a seven-inch tablet that retails for $250. The device, which comes with Ice Cream Sandwich and Google’s application store, compares favorably with the Kindle Fire. Although it’s not quite as cheap, it has slightly more RAM and some of the performance and technical advantages of ICS. Such products could help Google keep its own flavor of Android competitive on tablets.