For the six months leading to March 31, 2012, The New York Times saw a strong growth in both weekday and Sunday circulation figures, according to a new Audit Bureau of Circulations (ABC) report. And it seems these gains are largely attributable to its popular digital subscription packages which were rolled out in March last year.

As we reported earlier this year, The New York Times has seen a pretty impressive uptake of its paid digital offering, racking up almost half-a-million paid digital subscribers in the year since it went behind a paywall.

The latest figures include both print and digital, seeing an average circulation of 1,586,757 for Monday–Friday, and 2,003,247 for Sundays, representing a 73% weekday gain over the same period last year, whilst Sunday has seen a 50% rise.

To bring some digital context into this, for the ABC reporting period the total average digital circulation for weekdays was 807,026, and for Sundays it was 737,408. This includes all “paid and verifiable digital subscription copies”, as well as paid subscriptions to replica editions and e-readers including the Kindle and Nook. It’s also worth noting here that The Times’ digital circulation constitutes roughly half of its overall circulation.

It also seems as though the inclusion of comprehensive digital access with every print subscription to The Times is helping to drive growth and reader retention, with Sunday home delivery circulation continuing to grow, rising by around 2% in the latest reporting period.

“This latest ABC statement illustrates the great strength of the overall New York Times brand and our strong performance in the period is a tribute to the success of our digital subscription strategy,” says Scott Heekin-Canedy, president and general manager, The New York Times. “In addition, we believe that the new ABC rules have allowed us to offer a true reflection of the actual cross platform usage of our products by our highly engaged group of paid subscribers.”

Back in March we reported that The New York Times was cutting back on the free articles it makes available, and starting last month the NYTimes.com paywall only gave access to ten free articles a month, down from twenty. It’s fair to say that it’s doing a pretty good job of building a sustainable publishing model that straddles print and digital, as it continues to report impressive numbers. Indeed, it’s becoming somewhat of a poster child for what a modern day digital publisher should look like.