Review on The 21 Marketplace by Jared Winebrenner

I like that it is an open exchange for API providers to list their products/services in order of popularity (as well as price). It's easy enough using Google Chrome or Firefox with some Javascript knowledge so there really isn't much learning curve here if you know how search engines work generally. There are definitely advantages when searching by category rather than just browsing through all results; however this can be accomplished via other means such as simply sorting them alphabetically instead. Having more control over what information gets displayed also helps keep me informed about my options without having to rely solely upon third party reviews which may not always reflect reality accurately - especially those from unknown sources who aren't looking out specifically for your needs but only trying to make money off any new customers they get into business with. This has been helpful since we're working within crypto currency space where trust levels tend.