A landing page is a page built for calling attention to a certain product with a call to action
such as creating an account or purchasing the product.
A great CMS will contain templates for modern website design, extra tools for HTML styling
, analytics for tracking how mnay people visit that page and how they got there.
Google Sites
Free to build a landing page with a form
By default, your form will published on a Google subdomain, unless you add a custom domain to your Google Sites page.
Launchaco
More like a single page website than a content page
Drawback: Not great if you constantly create landing pages, because they are mini web sites
they won't be able to be appended to your main web page, in fact they will contain a different URL.