When you have metrics - whether they are good or bad, they'll leave an impression. One of the best times to market your startup is before you've done anything at all because your story will shine through.
You don't want the audience that hates "vaporware" (no real product on the page), but rather the early adopters in the beta community. Use a platform like LaunchRock to help you capture emails and increase sharing (more on that in a bit).
Use the attached list to seed your startup or app - they might not all be relevant but there should be a high percentage you can close without too much effort. Others might take more time.
The goal of seeding is to capture emails - not just to let people know you're launching your product - it's to sell them on your products.
You don't want to create a new audience for each product, but rather create new products for you audience.
The next best thing to getting a credit card number is an email address. You shouldn't ask for everything - just the email address - if they are willing to give up this information, they are open to being sold on your product.