You can utilize ChamberWare's Referral e-mail system at any time you want.  Some chambers send out monthly letters notifying their members of how many times they were referred over the course of one month.  ChamberWare has the ability to do that very same thing through e-mail.  Plus you can specify the time period for your members referrals.  If you wanted to wait even longer and notify your members at the end of the quarter (every 3 months) you could set the dates to reflect this and ChamberWare will accommodate you.  You can also specify the subject and custom message that is sent to the members.