An online survey last year of 210 newspapers and business and consumer magazines, conducted by the agency that audits publication circulation numbers, shows that publishers are moving quickly to get their products on tablet computers and smartphones.

The move is motivated by the fact that those two platforms are more quickly moving toward profitability than websites, according to the 2012 survey conducted by the Alliance for Audited Media.

Of 210 respondents, 22 percent report that their smartphone and tablet platforms and apps are currently profitable, and more than half of all respondents said they expect those platforms to be profitable within the next two years.

Other findings include:

• Subscriptions are not the only revenue source for mobile platforms. The majority of respondents agreed a dual revenue stream from advertising and subscriptions is necessary to make digital platforms profitable.

• About half of respondents — 48 percent — have begun charging readers to read content on their websites. Of those still publishing online for free, 44 percent plan to begin charging readers in the next two years.

• The most popular way to charge for online content is a metered paywall, which is how the Register’s site operates. Customers may access a predetermined number of articles before payment is required. Almost 40 percent of the publishers said they use metered paywalls, while 17 percent require payment to read any content. And 33 percent use a combination paywall that restricts access to premium content.

Source: “How Media Companies Are Innovating and Investing in Cross-Platform Opportunities,” Alliance for Audited Media.