The Times now has more than 1 million international digital subscriptions.
We added a total of 455,000 net new digital subscriptions in the quarter, including 320,000 for News and 135,000 for Games, Cooking and Wirecutter.
Total revenues grew 19% in the quarter, with digital subscription revenue rising 28% and advertising up 40% for both print and digital.
As a result, adjusted operating profit grew 15%, despite a 20% increase in adjusted operating costs.
While COVID remained the dominant story, as it has for the last 20 months, a wide range of topics also captured the public's attention, including the Afghanistan withdrawal and the tragic events in Haiti, the resignation of New York's governor, and our ongoing climate reporting.
These are the kinds of stories that our 2,000-person journalism operation is uniquely positioned to cover with depth and thoughtfulness.
Net subscription additions to Games were 35% higher in Q3 than the prior quarter, and more than 20% higher than last year.
While a relatively small contributor to overall subscription additions, it's off to a promising start, especially among existing Times subscribers, with 10,000 net subscriptions in the first month.
It's a single destination for listeners to enjoy the full range of our audio storytelling, which today reaches 20 million listeners a month.
While year-on-year growth slowed in the third quarter compared with the second, as expected, digital advertising revenues grew 22% compared with 2019, the same rate of growth as we reported in the second quarter.
Adjusted diluted earnings per share was $0.23 in the quarter, $0.01 higher than the prior year.
We reported adjusted operating profit of $65 million, higher than the same period in 2020 by $9 million and $21 million dollars higher than 2019, which we continue to believe is an important comparison point given the impact that the pandemic had on our 2020 results.
As Meredith noted, we added 320,000 net new subscriptions to our core digital news product and 135,000 net new stand-alone subscriptions to our other digital products, for a total of 455,000 net new digital-only subscriptions.
As of the end of the quarter, we had approximately 980,000 Games subscriptions, approximately 900,000 Cooking subscriptions and 10,000 Wirecutter subscriptions, the Wirecutter subscription offering having launched at the beginning of September.
The international share of total news subscriptions remained at 18% as of the end of the quarter.
Total subscription revenues increased nearly 14% in the quarter with digital-only subscription revenue growing nearly 28% to approximately $200 million.
Digital-only subscription revenue grew as a result of the large number of new subscriptions we have added in the past year, continued strength in retention of the $1 dollar-per-week promotional subscriptions who have graduated to higher prices, and to a much lesser extent, the impact from our digital subscription price increase.
Digital news subscription ARPU for the quarter increased approximately 5 percentage points compared to the prior year and nearly 1 percentage point compared to the prior quarter.
ARPU related solely to domestic news subscriptions increased 6.5 percentage points versus the prior year and approximately 1.5 percentage points versus the prior quarter.
Print subscription revenues declined 1% as overall volume declines more than offset the benefit from the first quarter home delivery price increase.
Total daily circulation declined approximately 7% in the quarter compared with prior year, while Sunday circulation declined approximately 5%.
Compared with 2019, print subscription revenues declined 5%, as single-copy and international bulk sale copies declined, while revenue from domestic home-delivery subscriptions grew 1.7%.
Total advertising revenues increased 40% in the quarter, as both digital and print advertising grew approximately 40%, in large part as a result of the impact of the comparison to weak advertising revenues in the third quarter of 2020.
Compared with 2019, digital advertising grew more than 22% as a result of higher direct sold advertising, including traditional display and audio.
Meanwhile, print advertising increased 39% compared with 2020, primarily driven by growth in the luxury and entertainment categories.
However, print advertising remained below 2019 levels by 25%.
Other revenues increased 19% compared with the prior year to approximately $56 million, primarily as a result of higher licensing, commercial printing associated with the addition of the Dow Jones family of products to our operations, and Wirecutter affiliate referral revenue.
Adjusted operating costs were higher in the quarter by approximately 20% as compared with 2020 and approximately 16% higher than 2019.
Cost of revenue increased 9% as a result of growth in the number of newsroom, Games, Cooking and audio employees; higher subscriber servicing costs; a higher incentive compensation accrual and other costs in connection with the production of audio content.
Sales and marketing costs increased more than 65%, driven primarily by higher media expenses, which had been reduced last year in light of the historically strong organic subscription demand.
When compared to 2019, sales and marketing costs increased more than 30% while media expenses were approximately 54% higher.
Product development costs increased by approximately 18%, largely due to growth in the number of engineers and a higher incentive compensation accrual than had been recorded in the third quarter of 2020.
General and administrative costs increased by 26%, largely due to a higher incentive compensation accrual and increased headcount in support of employee growth in other areas, stock price appreciation on stock-based awards, and higher consulting costs.
We recorded one special item in the quarter, a $27 million gain related to a non-marketable equity investment transaction, which is reflected on the interest income and other line of our income statement.
Our effective tax rate for the third quarter was approximately 27%, which is in line with the rate we expect on every dollar of marginal income we report with the possibility of significant variability around the quarterly effective rate.
Moving to the balance sheet, our cash and marketable securities balance ended the quarter at $1.043 billion, an increase of $96 million compared with the second quarter of 2021.
The company remains debt free with a $250 million revolving line of credit available.
Total subscription revenues are expected to increase approximately 12% compared with the fourth quarter of 2020, with digital-only subscription revenue expected to increase approximately 25%.
Overall, advertising and digital advertising revenues are expected to increase in the mid-teens compared with the fourth quarter of 2020.
Other revenues are expected to increase approximately 15%.
Both operating costs and adjusted operating costs are expected to increase approximately 17% to 20% compared with the fourth quarter of 2020 as we continue investment into the drivers of digital subscription growth and compare against another quarter of low spending last year.

Summary:
Adjusted diluted earnings per share was $0.23 in the quarter, $0.01 higher than the prior year.
As Meredith noted, we added 320,000 net new subscriptions to our core digital news product and 135,000 net new stand-alone subscriptions to our other digital products, for a total of 455,000 net new digital-only subscriptions.
Total subscription revenues are expected to increase approximately 12% compared with the fourth quarter of 2020, with digital-only subscription revenue expected to increase approximately 25%.
Overall, advertising and digital advertising revenues are expected to increase in the mid-teens compared with the fourth quarter of 2020.