When Amazon launched its Appstore, it announced an exclusive deal to offer Angry Birds Rio for Android, and it even offered the game for free for a limited time. Later, Amazon signed a deal with PopCap games, making the Amazon Appstore the exclusive download point for PopCap's Chuzzle. Another perk of the PopCap deal is available for Android users today only: Amazon's Appstore is offering the Android version of Plants vs. Zombies for free.
Aside from inking exclusive deals, Amazon could also become a place of refuge for those rare apps that are exiled from the Android Market. For example, Google opted to play ball earlier this year with some carriers and block Market access to tethering apps such as EasyTether--but EasyTether is still readily available from Amazon.
But Amazon's Appstore isn't better than Android Market--yet. Despite offering a few cool extras, Amazon still faces an uphill battle in the app world, thanks to its late start and various issues that are still being worked out. To really jump-start its app business, I think Amazon's Appstore will need to start showing up as a native app on more hardware, perhaps of Amazon's own design.