Usage of videos on client sites

Hi. I would like to use tis plugin on client sites, but on the plugin page you say:

Our Premium members get access to use our API on up to 20 domains (and all subdomains). They can also use this within a WordPress multisite, that means support for hundreds and even thousands of websites.

Does this mean I can only use it on 20 client domains? I can't use it one every one?