The “you should backup regularly” argument needs little coaxing. Everybody “knows” they should backup the problem is they don’t. A backup plan is only as good as its followthrough – which is why Time Machine is so epic. It backs up every hour for you. You don’t even know it’s running but you hear the hard drive spinning, and watch your system slow down for a few minutes.
Once people jump on the backup regularly bandwagon, the sinkhole that many fall into is to stress the details: the absurd fear that some day there will be some file that they will absolutely have to have. And when that day does come they will discover that they have deleted the file – or overwritten it, or something else catastrophic – and thus, by not having that one file at the theoretical moment of truth they will not impress their fellow nerds in a, “Look what I kept for all these years. What do you mean, “so what?”” moment of glory.
A great post on the strengths and weaknesses of Time Machine. Like Shawn, I use both Time Machine and SuperDuper, but in different ways.