Google had something like a Chrome Extensions Center before this but then added apps that you can pay for and started calling it a store. Apple's Appstore also

Google had something like a Chrome Extensions Center before this but then added apps that you can pay for and started calling it a store. Apple's Appstore also calls itself a store, yet many of the downloads are free so calling it that is not misleading, at least in a new way. I imagine it is called a 'web store' since other stores tend to be either mobile (Apple, Android, ...) or desktop (Mac App Store, new Windows 8 Store coming next year) and it promotes the idea of a webbrowser being an operating system (albeit it is redundant).