Sounds a cheery subject, but it is important. Many writers rely on a sum of money dropping into the bank account from PLR (Public Lending Right) in February each year. We have our library readers to thank for this. A selection of libraries across the UK (and now Ireland) submit the number of times a book has been borrowed during the previous year. Based on this data, writers are paid a sum of money per borrow. Note it isn't all borrowings and they don't ask every library. There is an upper limit to how much you can earn, no matter how popular or famous you are. So pretty egalitarian, just like libraries in general. However, when you die, so does the PLR. No matter how often you're borrowed, your family/estate doesn't receive the monies. All well and good. However there are many agents/publishers/and family estates who still benefit considerably from a dead author's backlist. Think Enid Blyton and Catherine Cookson. If the books keep selling/get reprinted then the money goes to the estate. If they get borrowed from the library it doesn't.
One of the reasons why Catherine Cookson's books are all now appearing as ebooks.
So the moral of the story is? Get that backlist on ebook.
And check out Alanna Knight's books featuring Edinburgh based Victorian Detective Inspector Faro. http://tinyurl.com/3bsr64z This is the series that should have made it onto the screen. BBC thought about it a couple of times, but just went on making more Agatha Christie instead.