Askbug-theme Question Number of Licenses

Hi there,
first of all, thank you for your plugin. I am planning to purchase your theme but I do not know how are you counting the number of licenses.
I have two multisite installations (same site but different domains each one per country), Is it one license per multisite installation or per subsite?
Also, does the license expire? I mean will be getting the right to get the updates for free forever??
Thank you very much for your time!!

ps: I have not found this information in the site sorry if it is answered anywhere.