Yes Asus includes a sleeve so this is, strictly speaking, not entirely necessary. *however* it fits very well; as well as or better than the included sleeve, and it is thicker. Myself, I prefer the added protection.
As it happened, this was on sale when I ordered my Asus, so I paid roughly half MSRP. I do not consider that much of an outlay to protect a computer.
All that said, if you are happy with the one that came with the Asus, don't bother, but if you want a bit more protection... or some... more info
Complies with TSA security regulations:
I left my Eee PC in this sleeve taking it through airport security and it went through with no comment or problems. I removed the computer from my bag and put it in its own tray while still in the sleeve. I thought this information might be useful to other buyers. I like the nice fit of the sleeve and that I can fold back the top and charge the computer without removing it completely from the sleeve. The reversible colors are fun, too. It keeps the computer, which is made for portability, from getting... more info
Great Product:
Like this product a lot, i bougth it for my wife, and she love it BUT you have to know ASUS INCLUDES a sleeve with its notebooks. So, if you want to save $20 uses the one included.
Great!:
This is absolutely fantastic. It fits perfectly to Eee 900. Loved the red color. Loved switching colors (all black or all red) anytime I want.