New to Excel? Looking for a tip? How about a tip so mind-blowingly useful as to qualify as a magic trick? You're in luck. With this video tutorial from ExcelIsFun, the 368th installment in their series of digital spreadsheet video tutorials, you'll learn how to create and use an array formula that will permit you to count unique items within a column while specifying more than one criterion. This guide uses the SUM, IF FREQUENCY, MATCH, ROW, and ISNUMBER functions (in a somewhat unusual combination).