This site is under construction and is both very incomplete and subject to change.
The current cannonical site for documentation is here.

Do I have to share data with Freemius?

If you have installed a ***free*** plugin or theme integrated with the Freemius SDK, you’ll be given a clear “opt-in” form that allows you to choose whether you agree to share some data (explicit details about exactly what is shared can be found below), or, if you don’t agree, you can simply skip data sharing altogether. None of your data will be shared without your explicit consent – that is completely optional and up to you to decide.

If you purchase a ***paid*** plugin or theme that is sold through Freemius, your email address, first and last name, and billing information will be securely stored in our system in order to complete the purchase. Once you activate the paid product on a WordPress site, if the product is integrated with the Freemius WordPress SDK, you’ll be prompted to enter a license key to activate the product. The license key offers security for both you and the seller that your use of the product is genuine. By entering the license key, some information about the site will be shared and stored on Freemius for two reasons:
1. **Management:** We want to give you transparency about the sites where your new product license has been activated, including the version of the product, and other details described in the table below. This protects you against unauthorized activation of your paid license.
2. **Software updates:** Ongoing connectivity with the licensing engine is essential for receiving automatic security & feature updates of the paid product directly within the WordPress Admin dashboard. To receive these updates, data like your license key, product version, and WordPress version, is periodically sent to the server to check for updates.

This data collection and validation practice is the market standard in the WordPress product space, similar details are collected when purchasing and activating a license for themes, plugins, and add-ons that are sold through other eCommerce solutions like WooCommerce and EDD (Easy Digital Downloads).