I agree, I highly doubt that the percentage of storage that is non-unique is enough to increase Dropbox's profit margins significantly. I'm certain they use th

I agree, I highly doubt that the percentage of storage that is non-unique is enough to increase Dropbox's profit margins significantly. I'm certain they use this and several other techniques such that each user reflects a far less impact on Dropbox's storage than the 50GB bought, but if that's printing money than Amazon would be a first world country by now.