The plugin is designed to be lightweight and efficient:
Database checks only on version change: The plugin only runs database table creation and migration checks when it detects a version change (plugin update or fresh install). It does not run these checks on every page load, so there is zero overhead during normal site operation.
PDF download click tracking: Download page PDF link clicks are tracked via a lightweight AJAX request. This gives you accurate data on how many subscribers actually clicked to download the PDF, without relying on page view counts.