On the other hand, if sharing didn't count towards both parties' quotas, then you could just create an army of sockpuppets, each of whom shares their 2GB folder

On the other hand, if sharing didn't count towards both parties' quotas, then you could just create an army of sockpuppets, each of whom shares their 2GB folders with you. I understand that the Dropbox people don't want to make it that easy.