The source for Millionaire/Pension is a marketing database called Larksupr that banks, brokerage firms, and other financial institutions use to find their prospects. The database looks at over 70 different sources that provide clues to wealth, including subscriptions to magazines on financial topics, airplane registrations, boat registrations, Keogh retirement plans, and lists of investors from brokers.  It is often useful for pointing to hidden wealth. On average, we find data in Millionaire/Pension 10 - 15% of the time.