An interesting piece over at TV Tonight highlights a number of shows, including the most recent season of Doctor Who, and how the “overnight” ratings can severely under-quote a show’s penetration.

The average “overnight” ratings for Doctor Who this year was 565,000 (you can see the individual numbers in our earlier reports — they were very consistent week to week). This is an “instant” snapshot of the people in the big five cities (Melbourne, Sydney, greater Brisbane, Adelaide and Perth) who watched the show live.

But you can watch Doctor Who later by taping it; via an ABC2 repeat during the following week; and from somewhere outside the “Big Five”. And these numbers do get recorded and published, just not straight away, and hence they miss the big media splash. In the case of Doctor Who that 565,000 more than doubles, to 1,136,000!

On top of that there was an average of 178,000 views on iView (note this is based on completed downloads, not viewers, unlike the other counts). Experience from the UK and the BBC’s very similar iPlayer system indicates there is not much “double-dipping” between shows watched on TV and watched via the streaming services — so you could safely go with an average total viewing by 1.3 million Australians.