Facebook Applications: Where they live

I've been learning and thinking about Facebook applications, which everyone else is also writing and thinking about… I will be posting about some of the interesting facts and insights as they come up.

This one is fairly obvious if you think about it, but it may be a useful reminder.

_Facebook applications don 't ever let you actually store anything on the Facebook servers/service themselves. _

In other words, let's say you add a really cool Facebook application that let's you display and share all the books you have read, and let all your friends do the same. Everyone is writing reviews and marking thumbs up and down on these books, organizing them into bookshelves and what not.

All of that information is being stored somewhere else, not "at facebook". That is, not on their servers, under their control, under their security, backup and availability. They don't have any responsibility over it.

When you use the Facebook application it sure looks like everyone and everything is under one umbrella, but it's not.

Why might this matter?

• If the server on which your application's information breaks or dies, your information is offline or lost, irrespective of how big and powerful Facebook Inc is.

• While Facebook might have assured you that they will only allow authorized people to see, change or delete your info, this assurance does not apply to the information you entered via the application.

These observations are not profound and they are obvious from the structure of Facebook applications. But they are easy to overlook or assume wrongly.

Update: I just read a relevant post in Bill Ives blog about a new service called Workbook. Workbook is a Facebook application which allows users to access some of their secure information apparently through Facebook. Not the same as what I am talking about above, but relevant.