But again, you're not sending out to thousands. And you don't have to send them all out at the same time. I haven't used Kickstarter, and it looks like I can't as I'm not in the US. But I'd be surprised if they didn't give you some way to contact your contributors in bulk, and I'd be surprised if they gave you all the individual email addresses and made you do it. Maybe they do. Maybe you DO have to contact them all individually. But again, these guys are funding your development - aren't they worth it?