Everyone talks about the importance of social proof, but what's an alternative in the same vein that you can put on your landing pages BEFORE that stage when you are just testing an idea and want to entice early users?
Do you talk about social proof for yourself as the founder? I'm not super keen on bravado, but that's my only thought so far and interested in other ideas as well.
You're probably going to have to "do things that don't scale" to get the first few people to validate your idea with. Once you have a few people you can perform customer validation calls with, for those who are really interested or who love the Beta, you could ask them for a quote for your landing page?