Question Concerning License/Multisite

Hey there

Love the free version of this plugin but excited to try out the premium features. I was curious as to how this worked for Multisite when considering how many licenses to buy. If I buy 1 license is this good for an entire network of Multisite websites that can each use this plugin on their own blog/sub site?

Thanks for the help and hard work!

Mike

http://ww.wp.xz.cn/plugins/password-protect-wordpress/