You need to test your market to see if a landing page is a good idea.

I have a few niches where my landing pages killed sales and some where I'm able to
get build a list of 400 plus new names everyday for FREE.

But you just have to test out what works of you and what will not.

Check out this video blog post I did about landing pages.

http://moneymakingresults.com/?p=7

The key is you have to test. Some markets this works and others is fails.

Charles