The Audit Bureau of Circulations in the US has altered its definition of a digital magazine to include editions adapted for new readers such as the iPad.
From now on, digital editions must include a print edition's full editorial and advertising, but no longer need to have an identical layout.
Wired magazine was the first publication to ask the ABC to monitor the circulation of its of its iPad version. GQ has had an ABC-approved replica app for the iPhone and iPod Touch since December.
Digital editions are not yet included in ABC figures in the UK, but the US change points the way as magazines and newspapers move onto new platforms such as the iPad.
