I purchased the license fl-ccme-uc-5 from a reseller and all I got from Cisco was a Customer Entitlement Letter
(via Fedex.) Is there something I am missing to add to my 2821 router to increase the users?
You are "good to go" here
The Feature License is not loaded on box and is in fact
honour-based. You are free to add the new users to your system.