I write quite a bit here about event marketing, with most of it focused on how to reach prospects and encourage them to register for your conference, trade show or webinar. But there is a group of people who can be even more productive to your marketing efforts than your hottest list of prospects – the folks who have already registered for your event.

Here are a number of ways to take full advantage of your early registrants, to fill the room further, lift revenues and build buzz in advance of your event:

Team Pricing or Bring-A-Colleague: Chances are, there is more than one person at each prospect company who would be a suitable attendee for your event. And unless you have direct marketing skills that put Lester Wunderman to shame, you probably do not know who they all are. But the person from each company who has registered does know which colleagues are a good fit for your show. If you have a Team Pricing or Bring-A-Colleague offer, your pre-registrants are the perfect audience for it. Not only can they help your message fan out into their organization; they’re already highly engaged with the conference and are the most likely to spread the word.

Pre-Show Engagement and Activation: Tapping into the engagement of your pre-registrants doesn’t have to be limited to their influence over colleagues. Why not ask them to spread the word to their entire networks on Facebook, Twitter or LinkedIn? Each time one of your pre-registrants posts something about your show on their Facebook page or Twitter feed, they’re not just telling between 20 and 2000 people about it – by virtue of their own participation, they’re recommending your show. The best way to get them to do this – just ask. Use an email dedicated to this purpose. If they’re truly engaged, no incentives or gimmicks will be necessary. (You’re exhibitors are even more productive with this tactic – they typically have many more fans and followers and are eager to tell everyone what EXPO halls they’ll be in.)

Incremental Sponsorship Revenue: Your exhibitors are paying handsomely for the opportunity to be in front of your event audience. An “attendee update” newsletter delivered expressly to your pre-registrants is another piece of highly desirable media. For the 4-6 weeks preceding the event, create a micr0-newsletter for your attendees that goes out weekly, advising them of event logistics like hotel deadlines, agenda changes, networking opportunities – whatever information will enhance their experience at the event by saving them time or exposing them to the full breadth of what the show offers. Sponsors and exhibitors will likely find the newsletter an appealing supplemental sponsorship opportunity, as it helps optimize what they have already spent on the show by building some brand identity and interest before the event begins. An attendee update newsletter can also be a powerful value-add to close the high-level sponsorships, particularly if it provides exclusivity.

Get a Jump on Next Year’s Marketing: Sponsors are not the only audience that will benefit from an Attendee Update newsletter series. By prepping your audience for everything your show has to offer, you are helping to ensure that they take full advantage of the event and have the most rewarding experience possible. Certainly that serves the interests of this year’s event, and your programming and event operations staff will be duly grateful. But you’re also serving your own interest as the event marketer: people who love this year’s show are more likely to come back next year. That makes your job in 9 months a lot easier. Instead of communicating all that is new about next year’s event, you can simply remind people about last year’s event. This makes early registration earlier, which gives you an even larger pool of pre-registrants to market to the next time around. The virtuous cycle has begun.