The most obvious thing is to simply extend the deadline to anyone who will listen: "Due to overwhelming demand, we're extending the early bird discount ... etc. etc..." But while this generally gets you a few more enrollments, you also run the risk of pissing everyone off who busted their asses to meet the deadline in the first place, not to mention your credibility also suffers because everyone will realize there's no need to rush to sign up in the future when they can get the discount anyway even if they miss the deadline.
Personally, I confess I ALWAYS extended my early bird rate by approximately one week past the deadline to accommodate families who missed it for whatever reason. But that was until last year when I discovered a new way of doing things that works even better. "Works even better" means the strategy I use now doesn't piss anyone off (instead it makes everyone happy), keeps my credibility intact and increases enrollment even more.
If you want do the same thing, here's what you do.
You empower all the people who've already qualified for the early bird rate to extend the early bird discount to their friends; you grant them PERMISSION to offer the discount to their friends on your behalf.
Send an email to enrolled families saying you understand times are still tough for many people, but camp is getting full, and you imagine they may have friends who want to sign up but missed the money-saving deadline for some reason, and you'd rather fill your last remaining spots with people they know than others from the outside, etc. etc.
Then go on to say in light of this, as long as they promise to keep things a secret between you, them and their friends, you'll let them extend the early bird rate to just 5 of their friends as long as their friends sign up for camp this week. You can start your letter/email like this:
"Dear Camp Family,And then you go on to explain the reason you're writing and the details of your offer all that. Trust me, if you craft your message in such a way it conveys the impression you're doing them a favor by letting them offer the early rate to their friends, they'll be GRATEFUL, not angry, and they won't hesitate to start telling everyone they know how they swung this great deal with the camp on their friends' behalf and all that. It's almost funny, because you're making them feel important!
Please don't share this email with anyone EXCEPT YOUR FRIENDS who would like the same Early Bird discount you got when you signed up for camp..."
This is the perfect way to get more word of mouth enrollment in a quick period of time when you'd otherwise be waiting for the next registration to come in. It takes no effort other than writing the email. And instead of pissing anyone off who's already signed up, you come out smelling like a rose.
I urge you to try this tactic. It works!!! And it works the best when you send the email a few days after the initial deadline expires. I'm sending my email out in a few days (I'm using the exact same letter I used last year) and I'll let you know how it goes.