The company’s practice of offering heavily discounted promotions has attracted new subscribers, but has also lowered the contribution of each customer. In the first three months of the year, individual subscribers to the core news product generated an average of $11.94 in monthly revenue, significantly lower than the $14.95 the publisher took in per customer during the same period three years ago. Subscribers to the Crossword and Cooking apps, which are sold separately, have been paying a steadier rate.

Times executives said they expected the average rates of subscription revenue to decline modestly as part of the company’s overall strategy to reach 10 million subscribers by 2025. To do so, the company will have to sign up an average of 203,000 new customers every quarter.

Since the so-called Trump Bump at the end of 2016, when The Times booked a record number of subscribers after the election of Donald J. Trump as president of the United States, the company has generated an average of 200,000 subscribers each quarter. Maintaining that rate of growth will be challenging.

Major news events continue to be a driving force behind new readers, Mr. Thompson said on an earnings call with analysts Wednesday, and The Times plans to invest more in the newsroom.

“The mission of this company is to deliver great journalism to the world,” Mr. Thompson said. “We attribute the recent success of our digital strategy to the fact that this mission drives everything we do — including our investment decisions.”

The company separately announced the debut of a new site, Parenting, aimed at “parents who want help having and raising kids today.” The site is meant to be a stand-alone service like the Times Crossword or Cooking app, and The Times has the goal of turning it into another subscription product.

As The Times’s digital businesses grow, its print operation continues to diminish. Print advertising fell 11.9 percent, to $69.5 million, and print subscription revenue decreased 2.6 percent, to approximately $161 million.