Marketplace search indexes are updated on a weekly basis, so it can take up to a week after you add a product listing to your Marketplace Shop for that listing to show up in a search. New product listings should always be listed immediately in your E-junkie Shop here:
In actual practice, very few buyers actually come to Marketplace just to browse or search around; we simply aren't a major "shopping destination" site like, say, Amazon or eBay are. Most buyers using the Marketplace arrive there at a specific merchant's page because of that merchant's own marketing or advertising driving traffic directly to their own product pages.
Marketplace primarily serves as a place to offer your products for sale if you don't have, or don't want to build, your own Web site where you can sell products directly from your site by pasting your E-junkie button codes there.