kjhughes is correct. A lot of these pages are meant to gauge interest. If the market doesn't seem to be there the founders won't launch the product and you'll never hear about the product again.

At Beta List we try to be selective and only publish startups that have a custom designed landing page. This weeds out a lot of startups that aren't really dedicated to launching something. This tactic is obviously not fool proof so I welcome any feedback you might have: marc -at- betali.st