Hi Joe,
Personal and Business only refers to the number of sites the license key can be used on (one and three, respectively). You can use the “Personal” license on a business site or the “Business” license for your own sites, no problems.
The license key must be purchased or renewed each year. One purchase gives you one year of access to support, downloads, and automatic updates. After that, the plugin will continue to work, but you will not be able to update. Happily, renewals are at a discount price.
Cheers,
Leah