You can place subscribe forms on specific pages so readers can subscribe without being prompted immediately upon opening the publication.
First, make sure your collection has a free subscription enabled, or check the subscription status in the upper right corner of your collection toolbar.
Click the Actions menu and choose Subscriptions.
Go to the Free subscription tab.
To avoid asking readers to subscribe from the cover page, select No, don't show it from the popup option dropdown.
Scroll down to find the subscribe form settings. Choose the fields for readers to fill in, then copy the subscribe form link from the embed code box. The link starts after src=' and ends before 'style.
Open your publication in edit mode and go to the page where the subscribe form should appear.
Choose the web page plugin and paste the copied link.