The number of paid subscriptions to digital editions of magazines has leapt since 2007, according to the Audit Bureau of Circulations, reports MediaBuyerPlanner.

In the first six months of 2007, a total of 56 consumer magazines had fewer than 500,000 paid subscriptions to digital editions. However, by the end of last year, that number had nearly doubled, with 110 magazines reporting paid digital subscriptions of nearly 1 million.

The ABC has recently expanded its definition of digital editions to include electronic products - not including free websites - that are nearly the same as the source magazine, even if they’re not exact replicas. This change means that the number from the end of last year is likely to go up with this year’s June statements.

Without digital subscriptions, some titles would miss their rate-base guarantees. Cosmopolitan, for example, is the second-biggest user of digital subscriptions, with more than 99,000 in the first half of 2008. This accounts for 3.4% of its 2.9 million circulation - and more than half of those copies were free to recipients. The magazine surpassed its rate base by 26,683 copies, so about 75% of the digital copies counted toward the rate base.

Some media buyers find digital subscriptions to be worth less than their print counterparts. Scott Daly, EVP and executive media director of Dentsu America, thinks there is “absolutely no value whatsoever” to digital subscriptions, adding that if a magazine sold digital subscriptions as part of its circulation, the agency would likely discount it. “…A digital version of a magazine is not the reason we’d go into a magazine,” he is quoted as saying.

Robin Steinberg, SVP and director of print investment and activation at MediaVest is less adamant against digital editions, but said that selling digital subscriptions  as part of the rate base without clarifying the difference is “questionable.”