If you purchased a license prior to 2016, you paid a one-time fee and acquired a perpetual license that allowed you to use the software forever. However, it only unlocked the version of the software that was available at the time of purchase. For example, a license for version 7 wouldn't work with version 8. In 2016 we dropped this licensing model entirely and now sell annual subscriptions which allow you to use the latest version of our software (or older versions) for one annual price. Many of our subscriptions also include free survey hosting, but you are still permitted to upload surveys to your own servers. On our free servers, there is no charge for each survey or for the number of respondents. If you choose to upgrade from the free servers to your own dedicated server, there are additional fielding charges.