Senuti is free software, and we intend to keep it free as long as possible.
Purchasing Senuti now will ensure that if we ever create a paid version of Senuti, you will receive free upgrades. Forever. There is no catch. We want to give you incentive to purchase a license while keeping the software free for those who might not be able to afford it.
Since Senuti is currently free, purchasing a license is really the same as making a donation of $18 or more. If you think that it is worth more, feel free to donate any amount you would like.