There are many reasons why your Google Analytics possibly doesn't quite match up with the statistical data found in iPaper:
Different definitions of what a session is
There are several key differences in how a session is defined in iPaper and Google Analytics:
In iPaper 
An iPaper session is registered when a reader clicks your Flipbook URL and views it, saving a browser session cookie on their device (PC, Phone, etc.). As long as the reader hasn't closed their browser or turned off their device, returning visitors are not counted as new sessions.
The session is tracked as long as the cookie value remains the same. iPaper does not track unique visits, but this metric can be captured by integrating with Google Analytics.
In Google Analytics 
Google Analytics defines a session as a group of user interactions on your website within a specific time frame. A session can include multiple page views, events, social interactions, and e-commerce transactions.
A single user can have multiple sessions, which may span across the same day or over several days, weeks, or months.
A session ends in two ways:
Time-based expiration: After 30 minutes of inactivity or at midnight.
Campaign change: If a user arrives via one campaign, leaves, and returns through a different campaign.
These differences in definition, will naturally mean that the number of sessions recorder will vary across these two different analytics systems.
Is the Google Analytics script being loaded for all your visitors?
Another reason for differences between iPaper and Google Analytics can be attributed to the blocking of the Google Analytics or Google Tag Manager scripts.
Should the Google Analytics script fail to load, no Google Analytics sessions are recorded. However, as the iPaper data tracking script is built into iPaper, these sessions will always be recorded.
What's blocking my Google Analytics script from loading?
There are various reasons why advertising scripts like Google Analytics or Google Tag Manager might be blocked or fail to load during individual sessions. Potential blockers include:
Cookie banners
Cookie banners
iPaper's cookie policy feature blocks all advertising cookies unless visitors explicitly consent. This includes Google Analytics and GTM scripts, though iPaper’s session cookie ensures sessions are still recorded.
Google Analytics blocking browser extensions
Google Analytics blocking browser extensions
Some users have tracking blockers installed on their devices. However, iPaper’s engagement tracking tends to go undetected by these blockers.
Browser privacy settings
Browser privacy settings
Some browsers (e.g., Brave) block Google Analytics by default. iPaper, however, still tracks visitors in these privacy-focused browsers.
While iPaper’s session tracking differs from Google Analytics, it often results in higher session counts in iPaper due to bypassing potential blockers, leading to more sessions recorded in iPaper than in Google Analytics.
Please note, this is only a partial list of reasons why your Google Analytics data may not align with session counts and other statistics in iPaper. Due to the unique setups of our end-users, there are many other factors that can cause differences between Google Analytics and iPaper.