We live today in an almost incomprehensibly complicated world. Next week I am going to be visiting the United States. When I send an email from my BlackBerry whilst there it will depend on ast least the following things:
– the device's battery
– the BlackBerry OS and mail app
– no other app on the device lousing things up
– the device's transmitter
– the cell of whichever mobile operator it is that my device has latched on to
– the routing infrastructure of that mobile operator
– their links to the internet
– the RIM BlackBerry data network
– Amazon Web Services and their connections to the internet
– Microsoft Windows Server
– BlackBerry Enterprise Server
– the clever kludge that Google have written to make BES talk to Google Apps
– Google Apps
– Google's internet connections
– the email infrastructure of whoever it is that I am sending the email to
– the email client infrastructure of the recipient
Now whilst many of those individual elements may have service level agreements attached to them, there is no way in which I can sensibly give an assurance of the availability of that end-to-end service that actually means something to the end consumer of the service.
In fact, other than as arse-covering of a fairly granular level, is it possible to offer a service level on anything that actually is important any more? I'm not sure that it is… But I am also not sure what we can do to replace them as I'm an atheist and so prayer isn't a credible option for me.
mmitII 
I think there's an interesting dichotomy related to today's highly complicated, instant communications, multimedia society. On one hand, people tend to expect relatively swift responses (via whatever medium they have chosen). But these days, we're so used to hearing “my BlackBerry isn't syncing” or “my broadband is down” or “my email notifications for Twitter direct messages seem to have stopped” or whatever that nobody bats an eyelid when you don't reply at all…