"Selling to your existing customers is orders of magnitude easier than selling to new customers. We’ve never really strictly enforced the quotas differentiating our tiers from each other, so I had poor visibility into how many people were over quota, but it turns out that it is almost 10% of the user base. I built out capability in our billing system to upgrade a user’s account without forcing them to log in and initiate it themselves. Then I built a screen in our admin dashboard which shows all the accounts that are over quota and links them to their contact details in the CRM."
How great is it for a customer to hear that they've gone over but it's OK? So many companies would put a sting in the tail of the contract and charge overages (frequently at nasty rates), or just suspend their account until it's upgraded. Instead it's being used as a perfect opportunity to upsell an existing, qualified - and therefore presumably very happy customer - on a bigger plan.