Some investors don't yet appreciate the value of a promise.  When one invests in a stock, or buys real estate, no one promises to return the investment.   If the investment goes down by half, everyone involved understands that is the risk assumed upon purchase. 

Many don't want a risk like that.   We prefer some responsible institution to promise to return our capital.    In exchange for their promise, we are content with a lower reward.  If one really considers the riskiness of many investments,  it would be reasonable to pay  someone who promised to keep our money and  return it safely in a year, wouldn't it?

Will Rogers knew this.   He said, "I'm more concerned about the return of my capital than the return on my capital.    Will Rogers owned a lot of CDs. 

Those who are the stewards or owners of core capital know the wisdom of a promise.   We hope our readers will learn to appreciate the security of a certificate through observation, a gentler teacher than bitter experience.