I've just realised something interesting. When it comes to published works, I will read any number of books to catch up. Take the Song of Ice and Fire, I have all the books and they are huge. The same goes for the Sharpe books, the Bond books, and the Tru Blood books. The difference with these though is that there's a definite starting point. I think it'd help if writers do an index in the opening post of their fics, like how novels have the books in the series in the front. It'd be as easy as clicking a link to get to the beginning.