Last month, Amazon launched its own Android App Store and was promptly sued by Apple for using the term "app store." Amazon has since responded in court, calling Apple's claim to the App Store trademark baseless, and pointing to a statement from Apple CEO Steve Jobs for evidence in its favor.

The Seattle-based online retailer has asked a federal judge in San Francisco to throw out Apple's trademark suit, calling the phrase "app store" generic and not something that Apple can claim for its exclusive use. In the 10-page filing (PDF, via GeekWire), Amazon quotes Jobs, who, when speaking on Apple's quarterly conference call last fall, repeatedly referred to app stores in a generic sense:

So there will be at least four app stores on Android, which customers must search among to find the app they want and developers will need to work with to distribute their apps and get paid. This is going to be a mess for both users and developers. Contrast this with Apple's integrated App Store, which offers users the easiest-to-use largest app store in the world, preloaded on every iPhone.

Microsoft started the legal battle against Apple's trademark of the term app store, and ended up effectively representing all the companies that want to or are already trying to use the phrase. Amazon now appears to be agree with Microsoft's core argument: that "app store" is as generic as "shoe store" or "toy store." As a result, the term should not belong to one company.

Three months ago, Microsoft asked the US Patent and Trademark Office (USPTO) to reject Apple's application to trademark the term "App Store" because it is too generic. Apple countered back by reminding Microsoft that it successfully trademarked "Windows" a few decades ago.

Last month, Microsoft filed yet another legal filing against Apple, citing Amazon's new store as evidence that other companies need to be able to use the phrase to accurately describe their mobile application marketplaces. The issue is still in the hands of the US Trademark Trial and Appeal Board and will hopefully be resolved in the next few months.