Wall Streeet Journal e-Reader Subscriptions: What Do The Numbers Means?

There’s quite an interesting conversation unfolding over on Business Insider this week. Yesterday, contributor Joe Pompeo wrote a post on how the Wall Street Journal seems to be vastly outpacing other publications, including rival (for the sake of sensationalism, at any rate) paper The New York Times in terms of e-reader subscriptions. Pompeo breaks down the subscriptions by numbers taken from a report by the World Association of Newspapers using date from the Audit Bureau of Circulations (or the ABC, for the sake of brevity):

The Journal had generated 414,025 e-subscriptions as of April 2010, up 8 percent from 383,199 in April 2009.
By comparison, The New York Times ranks No. 3 on the report’s list of the top 25 e-reader circulations, with 90,934 downloaded as of this April versus 43,844 as of last.

But, as Business Insider CEO and editor in chief Henry Blodget asked in the comment accompanying the post, what do these numbers mean? How are we meant to interpret them?:

We need some definition of terms here.
The vast majority of the WSJ’s subscriptions (and I thought they had closer to 1 million) are bundled with the paper subscriptions. So what is the 419,000, exactly?
Similarly, what is the 90,000 for the NYT? The NYT doesn’t charge anything for its web site. So are those all Kindle subscriptions?

PaidContent’s Staci Kramer, who had covered an earlier, related report on e-edition circulation numbers, offers some illumination:

Thanks for the note, Joe. Part of the confusion here stems from the idea that e-editions equals e-reader or web/mobile subscriptions, which is not the case.

Neal Lulofs, SVP of Audit Bureau of Circulations, chimed in to voice his agreement, noting that the paid circulation numbers the ABC counted in its March 2010 FAS-FAX report is for all qualifying electronic/digital editions of newspapers and does not solely count e-reader devices.