It looks like iOS developers can now use AppStore.com URLs for advertising.

Creating easy-to-read short links to the App Store for your apps and company

You can also create easy-to-read links to your app using App Store Short Links, which use the AppStore.com base URL plus a specific form of your app or company name. This provides a simple way for users to find your apps on the App Store directly from your website or marketing campaigns. These short links are ideal for use in offline communications materials like print ads, TV spots, app trailers, radio ads and billboards.

The domain(Appstore.com/StarTrekApp) appeared on the Super bowl ad of Star Trek movie.

Apple Debuts New AppStore.com Vanity URLs For Developers During Super Bowl

AppStore.com links are not configurable, and the URL could be the company name(e.g., http://appstore.com/milkdrops/) or the app name(e.g., http://appstore.com/beentogether)