“How many times have you flipped through a magazine in line at the checkout counter before deciding to buy?” is the question Adobe posed to readers last week when they released their new digital publishing tool.
On September 8, Adobe Digital Publishing Suite developers released a new version of “Article Preview” with an new feature, “Alternative Free Article Preview Experience”, which allows publishers to provide previews of free articles in a magazine issue on iOS. The new beautifully designed user interface and preview tool is configured by publishers to“...pique readers’ interest with select free articles while also encouraging them to purchase with teasers of other articles within the preview experience. Readers will [also] be able to enjoy the full experience of free articles while being prompted to buy or subscribe when they navigate to other articles within the publication” 
Publishers and Developers: Learn how to configure "Free Article Preview" here
 Source: http://www.adobe.com/devnet/digitalpublishingsuite/articles/configuring-alternate-free-article-preview-experience.html