According to US publisher Hearst, 7-inch tablets are driving online subscriptions to women's magazine titles.

Speaking at the All Things D "D: Dive Into Media" conference in California on Tuesday, Hearst Magazines President David Carey claimed that tablets with a smaller screen that will fit inside a purse are leading to rapid growth in female subscribers.

In a discussion with All Things D's Peter Kafka, Carey revealed that 40% of its total unique views on its magazine webpages are mobile but that the majority are still from smartphones.

However, the company does have 900,000 US tablet subscribers.

He also explained that when the original iPad launched in 2010 the company thought it would solve the problem of digital subscriptions and selling virtual copies of its magazines, but that thinking didn't quite work out that way.

"Our men's products did well on the 10-inch iPad, but our women's products did not. But, they did really well on the 7-inch units -- something that you can easily slip into your purse.

We saw the 7-inch devices having more traction with women, while the larger 10-inch devices had more traction with men."

"We're really happy that Apple introduced the iPad mini, and we're awaiting the most recent numbers on how our publications are doing on that," he said.

However, there is another growing tech trend that could also generate more digital subscriptions but could also generate more costs for publishers -- smartphones with giant screens. "While we love the varying screen sizes for consumers, as a publisher there are enormous complexities in formatting our materials for so many screens," he said.