Something a friend of mine pointed out when people tout those sales numbers: they're JUST on Diamond orders. It doesn't account for collected edition sales for people who "wait for the trade." It doesn't account for Comixology (sales numbers aren't usually available, I believe). It doesn't account for Marvel's own digital subscription service. All those things would definitely move those numbers.
Those variants, though? That's fucking ridiculous and a PERFECT example of selling comics the wrong way. As the article points out, variants in the 90s like Adventures of Superman #500 nearly killed the industry.
If I ran a comic store, I would ignore all those variant deals. Of course, if I ran a comic store, I'd do it similar to a shop I frequented in Toronto, where they put 90% focus on graphic novels and collected editions. They also had a great incentive for customers: buy 10 books and get the 11th free based on the average of the 10 books.
EDIT: Gah, I keep editing this post. Sorry. A friend of mine also pointed out another one of Marvel's problems: they basically shuffle the same writers around their biggest titles. Bendis, Spencer, Waid, Aaron, etc, basically move from one big title to the next and there's rarely any new blood being given a chance.