Google AdWords mobile allows you to put your ads in the search results pages on mobile devices, websites, apps and video. We live in a mobile world with people absolutely obsessed by it and you should, love it or not, be involved with it if you want to move forward.
It is also a well known fact that people no longer use a single device to connect to the internet but use a whole range such as laptops, desktops, tablets, mobiles etc.
If you are a website owner then there is no excuse for you to not have either a responsive or mobile specific web site. To setup a mobile campaign, you can use enhanced campaigns in AdWords which are a recent change in AdWords that lets you focus on mobile devices.
Google have said that this is their way of being able to target multiple devices and location as they can be used to seperate them from tablet and desktop users for example.