Well, two factors there - #1, stuff like
Backblaze is pretty awesome. In this case, you get unlimited backup for $5 a month. If you need a fast recovery, you can have them ship you a USB stick or hard drive with your data on it for $100 - $200. So the system takes care of everything for you, with no initial hardware investment, and does it off-site.
#2, on the flip side, you're stuck with really slow upload speeds. Even high-speed upload connections are not very fast, so uploading HD videos of your family into the cloud can take forever. But, if your house burns down or your computer gets stolen or whatever, your local USB backup drive goes with it, so the cloud is nice for that. I use both...USB backup (Time Machine & SuperDuper) and cloud backup. It's all set & forget, which is really nice!