How about a discount for existing subscribers when they renew?

A few days ago, just a couple of weeks after I'd renewed my developer membership of WPMUDEV, I received a 40% discount code from Manage Wordpress - if my renewal date had been just that bit later I'd have been able to cancel and take out an entirely new subscription and saved myself over $125....

How about encouraging existing and loyal members to renew at a discount as well as encouraging new blood?