WPSSO Core Premium is licensed per WordPress Site Address URL, and each purchase (of one or more license packs) is assigned a unique Authentication ID number. This Authentication ID allows you to install, upgrade and activate the Premium version on one or more sites, up to the number of licenses purchased.
Discounts are available for purchases of 2 or more licenses. The 2 license pack is a good choice if you have both a Staging and Production site (as offered by WP Engine, for example). Sites that are load-balanced across several servers only need one license since they use the same WordPress Site Address URL on all of the load-balanced sites.
Sites within a WordPress network / multisite use different WordPress Site Address URLs, so each blog wanting to use the Premium version uses a license. The SSO settings in the Network admin interface allow you to define a default Authentication ID for all sites (which can also be customized / modified in each site’s Licenses settings page), or force all sites to use the same Authentication ID.
Take note that the default blog (ie. the BLOG_ID_CURRENT_SITE) must be licensed as well – to allow Premium version updates from the Network Admin interface – so purchase a license pack accordingly (at least one for the default blog). See the Multisite / Network Support notes for additional information.
As an example, if you purchase 5 licenses, you will receive a single AAs an example, if you purchase 5 licenses, you will receive a single Authentication ID, which you can re-use for 5 different sites (aka WordPress Site Address URLs). You can also get 5 individual Authentication IDs by purchasing a single license 5 times.
As a service to our customers, we also offer the option of merging 2 or more Authentication IDs under a single Authentication ID number (to ease license management issues). If you would like to merge 2 or more Authentication IDs, open a new support ticket and include all Authentication IDs to be merged in your request, along with the Authentication ID number you would like to keep.