Cubbsters are given 1GB of additional space every time they refer a friend into Cubby.

ENGADGET: LogMeIn's Cubby offering up 1GB for referrals, tells Dropbox where it can store it

In fact, in most of the industries that he studied, the percentage of customers who were enthusiastic enough to refer a friend or colleague perhaps the strongest sign of customer loyalty correlated directly with whether they actually recommended the firm.

FORBES: Measuring Business's New Bottom Line: Customer Delight