Teri kindly sent me the following explanation of their approach.
We made the decision to not link our market tests on our home page because we want, as much as possible, for the product to stand on their own. Same with press releases and and wacky PR stunt – we want people to help us build market tested and approved products that have been compelling enough on their own to make money.
We purchase advertising for our market tests (with Google Adwords and BlogAds) to support them.
While we do not mention the market tests on our home page, mention them to the community so they can see what’s happening with their ideas.
No information is currently available about our market tests on the site. It’s a part of our secret sauce.