Offering a free domains with your products ?
This hook will notify you when a user has a free domain, without a valid product assigned to it.
Meaning, he is getting a free product – when he shouldn’t !
Some real life example usage –
Client ordered a yearly hosting plan and received a free domain with it.
After couple of months, client cancelled the hosting account, but domain is still listed in WHMCS as a free domain and might be sent to the registrar for renewal !
This hook will look for these criteria (with some more verifications) and will notify you about it.