If you use WordPress multisite it can be a pain to have to put the licence key into every site for plugins that require a key.
Some plugins allow you to licence the whole multisite at once.
Two that I use all the time like this are:
- Gravity Forms
These statements added to the bottom of your wp-config.php file will do the trick for you.
/* define gravity forms serial */ define("GF_LICENSE_KEY", "put-your-key-here"); /** Define WordPress.com API Key */ define('WPCOM_API_KEY','put-your-key-here');