Subscriptions
Data Used: To initiate and process subscriptions, the following information is used: subscriber’s email address and the ID of the post or comment (depending on the specific subscription being processed). In the event of a new subscription being initiated, we also collect some basic server data, including all of the subscribing user’s HTTP request headers, the IP address from which the subscribing user is viewing the page, and the URI which was given in order to access the page (REQUEST_URI and DOCUMENT_URI). This server data used for the exclusive purpose of monitoring and preventing abuse and spam.
Activity Tracked: Functionality cookies are set for a duration of 347 days to remember a visitor’s blog and post subscription choices if, in fact, they have an active subscription.
WordPress.com Stats
Data Used: IP address, WordPress.com user ID (if logged in), WordPress.com username (if logged in), user agent, visiting URL, referring URL, timestamp of event, browser language, country code. Important: The site owner does not have access to any of this information via this feature. For example, a site owner can see that a specific post has 285 views, but he/she cannot see which specific users/accounts viewed that post. Stats logs — containing visitor IP addresses and WordPress.com usernames (if available) — are retained by Automattic for 28 days and are used for the sole purpose of powering this feature.
Activity Tracked: Post and page views, video plays (if videos are hosted by WordPress.com), outbound link clicks, referring URLs and search engine terms, and country. When this module is enabled, Jetpack also tracks performance on each page load that includes the Javascript file used for tracking stats. This is exclusively for aggregate performance tracking across Jetpack sites in order to make sure that our plugin and code is not causing performance issues. This includes the tracking of page load times and resource loading duration (image files, Javascript files, CSS files, etc.). The site owner has the ability to force this feature to honor DNT settings of visitors. By default, DNT is currently not honored.