I'm not that concerned with the sales... Moe and Miku are still relatively new, and Maho doesn't have many large roles yet. But they're starting to pick up speed with releases and roles again so I think they'll pick up a bit more soon. The anime they have done songs for lately haven't been quite as high profile lately (this anime is only a half-length show, around 13 minutes) so it's not really that shocking, but they'll probably sell better when they have a more mainstream anime to sing for, and when the members are a little more high profile. It'll take time but I think it will happen. There's a lot of young seiyuu out there now and things are starting to turn over to them in terms of roles and such, so I'd expect to see a lot more of all the StylipS girls from now on especially.
Anyway I got my second copy today... The artist edition this time. The wait wasn't too hard... 
I'll be honest, I still have trouble telling apart Moe and Miku's singing voices (though in just talking I can differentiate fine). Both of them have a "cute" voice and it's just a bit hard to tell apart at the moment... But I'm working on it... I feel bad when that happens but sometimes it just does... (I kinda wish the duets were senpai/kouhai instead of split by generation, so I could learn the voices a bit more...) Nocchi and Maho have pretty unique voices in general and especially compared to each other, and even compared to the others... I'm sure I'll master learning their voices eventually though. Especially now that I have the version of a single with a DVD! So yeah, gonna go watch the PV now and I'll come back and tell you if I improved any. LOL
EDIT:
Watched the DVD! Oh man it's been AGES since I've watched a "making of" video... I almost never watch those. I figure, once in a while, it's good to watch something different. I really liked the dance shot full version though. (Helped me figure out Moe and Miku's voices a bit better too, yay!) I love the dance formation, it's pretty great. The dance itself is really cool, and the way it just works so well with the line distribution and 4 members specifically, it's really great. It just gets better and better. Love the end pose!
If there's any single to get the more expensive version of, it would be this one. Maybe I'm biased since this is probably my favorite StylipS song (lol) but seriously, it's the first single to have bonus tracks not on the cheaper version. And the dance is really awesome.
They are abit late if this is the album song.
