This came out around the same time as Madoka Magica and has a similar premise. Despite Madoka's popularity, I would have to say I prefer Mahou Shoujo Site.
While it didn't impress me much at first, the story becomes more and more intriguing and fleshed-out as it progresses. Many of the characters, which read as tropes initially, are given interesting character development. Aya, for example, appears to be a typical "sad, abused loli," but she proves to be very cunning and capable in the right situation. She still hasn't completely avoided the stereotype (largely because her backstory is too pitiful and dramatic to be believable), but her character seems to be going in a good direction. I was also surprised that Sarina, the "typical bully", became such an important character. I also like the
As for the art - I like it, but at times the anatomy gets a little weird. However, it's pleasing to look at most of the time.
As I said, the story shares many similarities to Madoka, but I think it's a little more complex and well-thought-out. It also has some themes that are unusual for a manga of this type, like revenge. It's true that the story has many tropes, like the "mysterious website" and the "manifold misunderstanding" between Sarina and Aya; however, while it follows some tropes, the story also avoids others.
I've given this an 7 tentatively. I feel like the story right now (at ch. 17) is at a tipping point where it will either flourish or fall short.