An example I can think of: Imagine you sell "Webpage designs" online, vs "Wordpress themes". Your wordpress design site will get listed on design sites, you can

An example I can think of: Imagine you sell "Webpage designs" online, vs "Wordpress themes". Your wordpress design site will get listed on design sites, you can get added to the theme section of wordpress.org, lots of people will search for your keywords. Wordpress themes is a busy shopping street. The app store analogy holds - the app store can be thought off as a mall where people are walking about. If your store sucks, nobody will come in, but people are seeing it. If there was no such store, your app could potentially be on the web and you only ever have 10 visitors.