If your app includes retail folios, you can use a number of different methods to provide free content to your customers.
Publish one of your issues as Free and Public so that users can download this issue even if they don't have a subscription. You can specify a Publication Date in the future to keep the free folio at the top of the list, or you can specify a Publication Date in the past to keep the free folio at the bottom of the list.
One drawback to this approach is that you're frequently giving away outdated content or a limited amount of content that doesn't adequately represent your app.
If you select the "Enable First Issue Entitlement" option in the Account Administration tool, you make the most recently published retail folio available to users who download the app for the first time. Using this method, you improve the experience of first-time customers. You can also specify settings in DPS App Builder to determine whether the entitled folio is downloaded automatically when a user downloads the app for the first time, and you can specify whether that downloaded folio is opened automatically.
When you submit your app to Apple, we recommend that you have at least two retail folios so that Apple can test in-app purchases.
For best results, let your customers know that you're offering a free folio. You can do this by creating a library banner or HTML content that uses an API to determine how the folio was downloaded and displays conditional content. For examples and instructions, see First Folio Free and Digital Blow-ins.
If you're an Enterprise customer, you can prompt users to sign in before downloading the free issue. See Enabling promotional entitlement with Digital Publishing Suite.
For best results, use either First Folio Free or the iOS Free Trial Subscription (described later in this article), but not both.
If you select "Enable Article Preview" in the Account Administration tool, any article marked as "Free" in a retail folio will be available to users for downloading and viewing. Any article marked as "Metered" includes a "Read Article" button displayed in the purchase pane that appears when users navigate to that article. The number of metered articles users can read is determined by the Paywall Threshold setting you specify. When users view any article that is protected, they see a paywall that prompts them to purchase the folio or subscribe. This option is available only for the iPad.
Use the Account Administration tool to enable article preview. Use the Folio Producer Editor to change Article Access settings: Free, Metered, or Protected. Make sure that the Viewer Version of the folio is v27 or later. If you're updating the viewer version of an older folio, update all the articles within the folio after you change the viewer version.
For details about free article preview and other advanced techniques, see Free Article Preview.
Apple iTunes Connect includes settings for enabling a free trial subscription for your Newsstand subscription app. When specifying the duration, you can select a free trial option and a marketing opt-in incentive option.
For more detailed information, see this article about Promoting free content to gain new readership.