So I started using Dropbox again after not using it for a couple of months. Previously, when I drop a file ...say 500MB onto the folder, the Dropbox taskbar icon would show that it is uploading at about 40kbps. Today I dropped a 700MB video into the folder and it finished uploading to the Dropbox server in less than 15 seconds! I verified that the file was indeed on the server as a friend downloaded the file at a whopping 900kbps. So.. how the hell does Dropbox take my 700MB video and put it on their server in less than 15 seconds? My theory is that they look at files in other people's account to see if there is already one, then they just copy the info onto my account. Can anyone verify this?