For those that didn't know, War And Peace is approximately 560,000 words. So any story that has more then that is longer then a book famous for being "too long to read"

We have about 3 stories now that are over a million, and one that has surpassed two million.

Think this could be explained by observing fanfics are typically serial by nature. Authors can get away with length due to a large fraction of the reader base reading not reading it all at once.

This actually raises an interesting question: How much planning do longfic authors engage in and how much of it is improv'd? I know most of them have general idea of where their fic is going, but it'd be interesting to have concrete data.