Let's try this thought on for size. Avengers Academy. Most who read it will tell you, based on the letters page alone, that this title is considered very important to its readers, as evidenced by letters from both the teen-community and/or the gay-community. Both groups (or three groups, including the crossover between the two) consider this a flagship title for themselves.
To me, this title has not only 'established a voice' but has a loyal following clamoring for more comics like this one.
So, what does Marvel do? They cancel it.
That decision makes little sense, on too many levels. I don't know what its sales numbers were (Phil can probably find that out for me), but i would be willing to bet that there are a few series that sold less than it that are still continuing, and currently it is outselling ALL of the 'new' series that Marvel has announced it is putting out - a bird in the hand is worth two in the bush.
Once again, i see this as Marvel not knowing their target audience at all.