Maybe I'm being cynical here -- I'm not a web developer but have lots of experiencing managing web-based products -- but if you want to have state you should store it in the cloud, because local devices are volatile. Xbox Live, for example, uses a fairly simple service for cloud saves for games; local saves still happen but any developer has the option to push saves to the cloud. The author definitely raises good points about how it's easier for developers to not have to worry about it, but cloud saves have some hefty benefits, like multi device support, user getting a new device, etc.