As a team member of dotMobi -- the company behind the .mobi domain as well as mobilization products like the goMobi mobile site builder and DeviceAtlas device detection solution -- I can tell you that the .mobi domain addresses several issues. In fact, we wrote an overview of that on our website at http://dotmobi.mobi/content/aboutmobi:
.mobi is the de facto standard for identifying mobile-friendly Web content
The mobile Web continues to grow exponentially. In 2012, the U.S. audience for mobile Web was up 82% over the previous year, according to Nielsen. Today .mobi enjoys the position of the most prevalent top-level domain in use for identifying mobile content.
.mobi domains are whitelisted by network level transcoders
Having invested money and time in creating a great mobile presence, you don't want a third-party transcoder modifying your site ... but this can happen when you use a non-standard name for your mobile Web site. Generally, .mobi sites are automatically whitelisted by all network-level transcoders, ensuring your site will render as you intended on all mobile devices.
.mobi domains offer better search engine performance
Crucial to the success of any business is search engine marketing, which grew from $15.36B to $19.51B from 2011 to 2012, said eMarketer. Because every .mobi domain registered gets its own entry in the Internet Zone File, your site will perform better than any other mobile naming convention. Additionally, search engines detect searches from mobile devices and prioritize their results accordingly. Because .mobi sites are high quality and made for mobile, they go to the top of the mobile search results.
.mobi names are designed for mobile use
Entering long URLs is cumbersome; you need a short name for your site. There are still millions of great .mobi names available for your content.
.mobi is actively promoted and industry supported
For consumers, it's essential that mobile content be easily found and navigated; it's this need that prompted ICANN to approve .mobi as the only domain specifically designed for fending mobile content.