Letters pages in comic books finally fizzled out a few years ago. The last one I remember seeing was in an issue of Captain America some way into Ed Brubaker's run. DC had already dropped them across their line a few years before that. Now neither Marvel nor DC run letters pages (as far as I'm aware). Which is a shame, because that's a window on the readership that's going to be lost for anyone looking back. Sure, there's the various internet message boards, but those threads don't necessarily stay around forever. Whereas a letters page in a physical comic book acts as a near-as-dammit permanent time capsule, shedding light on what the most fervent fans were thinking at the time.
Why is that important? Honestly, I don't know if it is. But I've been re-reading old Alan Moore Swamp Things, and the letters pages are often fascinating: the shock in the missives at Moore's first few issues (where Swampy's origin was stood on its head); the arrival as editor of Karen Berger, future Vertigo supremo. If you check the names of letter-writers in old comics, you'll often recognize a future comics writer or artist, firing off adolescent fanmail to their favourite book. In years to come, will we be able to look back at archived message board threads and spot the stars of tomorrow? Or have we lost something unique, something maybe even worthwhile?