How you convince someone to be interested and use bitcoin is dependent upon the target audience, but the three easiest ways to do it are:

1) Go to a store or restaurant that excepts Bitcoin and buy something with bitcoin in front of them (repeat if needed)

2) Send them a off the chain tip or gift with coinbase or changetip that gives them bitcoin without them having and account yet and lets you know if they setup an account to claim the free gift(by returning unclaimed)

3) Buy something on amazon for 15-25% off with purse.io or brawker in front of them and brag how bitcoin saves you so much money.