Up until now, subscribers of Enterprise Edition had to contact our sales team to add more users to their account at $3.5/user. We have now slashed the price and made it a much more simpler process. Using our newly introduced User Add-on , Enterprise Edition users can now purchase more users at $1/user directly. 

To add more users, go to your Subscription tab . If you are in Enterprise Edition, click on "Manage" under that edition and if you are in other editions, click on "Upgrade" corresponding to Enterprise Edition. Then select the number of additional users and Check Out.

Charles