Mobile sites have advantages
 

As more mobile users come online, mobile customized sites will gain in popularity and importance

Yes off-course, Mobile customizes sites will gain surely. As per Matt cutts If your website is not customizes in mobile than they will negative impact on your site. Today all people use smart phones so it is necessary to your website is open in Mobile and user can easily see and get information from your website.

Now most of the mobile users uses the smart phones, which is responsible for the popularity of the mobile customized sites...

Yes Mobile sites have advantages because your site easily open in mobile.