From TFA: "My second idea was to move to an open core model: hold back more complex or enterprise-specific features from the OSS version, sell those features as

From TFA: "My second idea was to move to an open core model: hold back more complex or enterprise-specific features from the OSS version, sell those features as an "expansion pack" on top of Sidekiq. Thus, Sidekiq Pro was born. This proved to be popular and forms my business today." http://sidekiq.org/products/pro http://sidekiq.org/products/pro http://sidekiq.org/products/enterprise http://sidekiq.org/products/enterprise