Start using bitcoin because it's different, fun to use and is the cheapest way to send money over the net.
This is the only reasonable answer that would apply to normal people so far, yet it shows a real use case problem for Bitcoin:
1) different: normal people hate different. They crave the familiar. Geeks like things because they are newer and different.
2) fun to use: this is money. Most people won't switch to something more complicated because it is fun to use. And in my opinion it's only fun to use because we like geeky stuff.
3) cheapest way to send money over the net: ok, this one maybe people will understand. People like to save money. But I mentioned to my parents that Bitcoin is so cool, because you can send 1milion dollars from point A to point B with no fees. And they said...of you had a million dollars to send, do you really think you'd care about the $20 transfer fee? zing! They shut me up!
These are good points, totally agree with those.
