Backing up your business data to the cloud should be a point of discussion with each and every one of your customers. I’m not saying that it’s necessary to do cloud backup, but it should be addressed.
One of the first questions that is generally asked is: “How long will it take me to backup my data?”
The folks at Highly Reliable systems posted an Upload Time Calculator which you may find useful. For example, it will take 8 days to backup 100GB of data on a T-1 line (1.5Mbps). But that time reduces to 2 1/2 days if your Internet upload speed is 5Mbps.