Ok, so I have been skeptical in the past of online backup solutions because on the front they appear to be a great deal, but when you get down to it... yuck!
Today I was listening to a TWiP podcast and the guys mentioned a solution that they used called BackBlaze I checked it out and ended up signing up right away. Some sites charge by the amount of disk space you use, and others charge by the amount of data transfer. BackBlaze simply charges $5 / month for each computer you want to back up. You get unlimited disk space, which is VERY handy for a photographer like me.
The key point that pushed me over the edge to looking at an online backup solution was Alex Lindsay mentioned his biggest issue would be if someone broke into his studio and stole his Drobo or the place burned down, all his photos would be gone forever. I got to thinking, I do have other backups of some of the older images, but nothing "real time" so that I would be sure not to lose anything. I was previously backing up my Drobo onto external hard drives, but if something happened to cause my Drobo to go bye bye, then it is very likely my external hard drives would be gone too.
Now with my Drobo and my online backup solution, I am very confident that my data is safe... that is... once the 216 hours it will take to copy all my data into "the cloud" has passed.