Typing a word into the merchant look-up will identify results. Merchants can also be grouped by product category.
New accounts must await an approval process that can take up to three business days, no instant setup-and-use.
The only way to find a merchant is to type their exact URL into the search box. There's no functionality to look up merchants in a general category.
Their solutions are link replacement, word linking, native ads, search results page ads and a few more.
Amazon is not currently on their list of merchants. There's a mention of it working with Amazon in Prosperent's forums, looks like it's available under Prosperent's approval but there wasn't enough information there to confirm it.