Michael Krasny

Auto dealer's son started used computer sales operation in kitchen after his $3, 3-line ad in the Chicago Tribune to sell old IBM generated high demand. Turned $300 profit on second sale. Founded Computer Discount Warehouse 1984; company became one of world's most profitable resellers of tech products. Retired 2001; company bought by private equity firm Madison Dearborn Partners for $7.3 billion last October. Donated more than $350 million in CDW shares to charity.