And then someone emails 'the' spreadsheet to someone else, and now you have 2 different versions and no rational way to reconcile them. neither is authoritative

And then someone emails 'the' spreadsheet to someone else, and now you have 2 different versions and no rational way to reconcile them. neither is authoritative anymore, and one probaby calculates the average of a list of phone numbers. (actual example...) They're great up to a point, and that point is sharing. I'm actually surprised that google docs hasn't picked up more traction for that reason alone. sharing a google docs spreadsheet doesn't cause divergence.