This is so far beyond pointless that I am tempted to just ignore it but why not take a swing... It's friday after all.
The average user spent "3,600 worth of time" creating all those emails. That is not to say that recreating them would cost exactly $3,600 because, as you can imagine, the email contents are NOT stored in the users' head. Recreating them all would be extremely difficult (and therefore come at a much higher price). Backupify has an interesting thesis (and certainly backups are valuable) but not assessing the *forward value* of those emails means that you pretty much cannot act on that figure.
this tool is not very accurate at all...it does not take into account the deleted messages, contacts and account longevity....you oldest message does not mean that you have had the account for that long....my oldest message was from 2006 and i know for a fact that the account was created sometime in 2004....same for the save data....it only accounts for the data that's present on the account...where is the server data, nothing is delete, all the emails old or new are stored somewhere....this is a big fail