I try to start similar dual-licensing model for my project. But I don't get this. The link page and "In order to unambiguously own and sell Sidekiq commercial products, I must have the copyright associated with the entire codebase. Any code you create which is merged must be owned by me. That's not me trying to be a jerk, that's just the way it works." - it has no legal value. I think all contributions are also LGPL unless contributor gives a consent to give up the change as commercial or public domain etc. In my opinion if Sidekiq Pro is forked from Sidekiq then Pro code should be released under LGPL or he should share part of $80k/monthly with all contributors. What about previous contributors' rights when the project switched to LGPL or dual? Can somebody explain this scheme?