Back to the Microsoft Ad: can you select a cell and not have the value appear in the formula bar? Yes. Also, a Microsoft PR guy claims the ad is *correct*, that they have not yet pressed Enter, hence the total hasn't updated. But you will see, frame-by-frame, that the chart updates as quickly as the AutoSum. Bottom line: It is a bad formula. Or Photoshop. Never do math with Photoshop!
Links in the video:
David Yanofsky
http://qz.com/143541/microsoft-botched-the-excel-spreadsheet-in-its-surface-tablet-ad/#143541/microsoft-botched-the-excel-spreadsheet-in-its-surface-tablet-ad/
Brad Sams
Alex Wilhelm at TechCrunch
http://techcrunch.com/2013/11/11/microsoft-didnt-get-its-math-wrong-in-that-excel-billboard/
David Shaw Twitter...