Yesterday, I started up my computer and an error popped up very quick. It said that there was a corrupted file on my hard drive and windows 7 could not be launch. I let it run its diagnosis and it told me to reformat my hard drive to before the corrupted file was added. I was kind of nervous to do that, but I did and everything worked out well. However, it got me thinking about what if I had lost all of my iTunes and Steam purchases. Now I'm in the market for an external hard drive to back up my purchases.
I don't want to spend very much considering I just built my computer a few months ago and it wasn't cheap. My local Fry's has a Seagate 1TB external hard drive on sale for $50. That's exactly how much I wanted to spend on an external hard drive to. The only problem is I can see is it doesn't have USB 3.0 or eSata. Although I'm not sure how big of an issue that is because I am only looking to back up files. I don't plan to run anything off of it in the foreseeable future. That could change but my internal hard drive still has more than enough space. Also, how great is Seagate? I remember when I was looking for my hard drive and I really didn't even think about Seagate. I heard great things about Samsung's Spinpoint series and I went with that.
Seagate make perfectly good hard drives, as do Western Digital and Samsung. Each have had problems from time to time (Seagate had a range of self-bricking drives for a while, but that's fixed; WD had REALLY annoying software on some of their external hard drives for a while; etc).
USB2 is slow. I suspect that's what the drive you are looking at has. It has one huge advantage - people have beaten on USB2 external hard drives so much that pretty much every possible glitch is gone.
Will it make a difference? Well, your backups will run slower over USB2, and if you are backing up many gigabytes, it could take quite a while, but it will work.
I prefer 2.5" external drives because they are powered from the USB socket - no transformer to lose (unlike 3.5" external hard drives). You can get up to 1.5TB in 2.5" at the moment.
If you get a USB3 external, you can plug it into a USB2 socket. It will run at USB2 speed on a USB2 socket, and USB3 speed on a USB3 socket, so that means it's only slow on PCs without a USB3 socket.
I have been buying Seagate GoFlex drives recently - I like the idea that I can plug in different interfaces if I want to. You can buy naked drives and use the GoFlex cable if you want, but the naked drives aren't protected afterwards.
BTW: Steam lets you download your games again, so all you lose there is the time and download quota. iTunes, not so much