I loved that Marvel published things like this back in the day. My personal favorite was The Transformers Universe, which did this for all the characters in their Transformers comics up through their adaptation of the animated movie, and I wish they'd done and updated one that covered the book's final run up through the early 1990's.

They're invaluable for quickly learning the back-stories of characters, especially ones that didn't appear very often, or that you weren't familiar with but appeared in a crossover event like Secret Wars. Awesome stuff. :)