I've seen a few posts before where they had a kickstarter like indicator for email collection. for some projects it seems like it might be helpful. video seems like a good idea but it seems expensive to build
This topic has been covered a few times before - here are a few:<p><a href="https://hn.algolia.com/?q=validate+your+idea" rel="nofollow">https://hn.algolia.com/?q=validate+your+idea</a>