I was in need of a new notebook a couple of weeks ago and thought about this, but there was something about it that just couldn't get me onboard.
It was a little bit unclear if any kind of leather/leather-ish cover came with it. I also have visions of dropping it and the clip somehow opening and all of my pages blowing away in the wind. I don't know if that's realistic, but a concern nonetheless.
Ultimately for $9 it's not enough of a savings for me to switch from my
go to Moleskine notebook. One lasts me almost a year, so I'll go ahead and spend the extra $7/year and have an expert do the binding for me.
You're still filling it with paper that has to come from somewhere, so I'm not sure I even accept the "eco" premise, though it probably helps to sell product.