How are sales monitored?

Nielsen Book monitors sales of all titles on a quarterly basis and alerts publishers when one of their titles reaches the threshold to qualify for one of the three awards. This includes sales through high street, airport, railway and internet booksellers as well as supermarkets for print books, overlaid with e-book sales from publishers through recognised retailers.

All editions of a book – paperback, hardback, e-book and film tie-in, where the full text is included, (but excluding audiobooks, sticker/activity books or any other version which is materially different) – are amalgamated and counted. To qualify, titles must sell more than 250,000, 500,000 or 1 million copies through the defined channels since the earliest original publication date.