Keep it as simple as possible...
Include incentives for them...
A decentralized system is far more secure than a centralized database... you can reference the recent security breeches with:
1) Anthem Blue Cross (80 million patient and employee records, potentially exposing names, dates of birth, Social Security numbers, email addresses, employment information and income data).
2) Ebay February 2014...compromising customer names, encrypted passwords, email addresses, physical addresses, phone numbers and dates of birth
3) JP morgan 2014... compromised usernames, addresses, phone numbers and email addresses.
4) Home Depot... 56 million credit card accounts and 53 million email addresses5
5) Significant others klike Sony, Target, Global Payments Inc., Tricare, Citibank, Heartland etc
You can mention the limited supply vs. the Fed reserve printing money at any time.
Large growth potential with a solution for the 2 billion unbanked...
http://www.worldbank.org/en/programs/globalfindex.
Nearly 1 billion in recent VC investments including Wall Street mainstays like the New York Stock Exchange, Goldman Sachs and the Fortress Investment Group.
Bitcoin is out performing all fiat currencies for the last five year average.
That enough for now don't want to overwelm them :^)