There are three key ways a mobile site will work for you. Mobile Search, Improved User Experience and an Extended Web Presence.
When someone does a search from a mobile phone Google detects that the person performing the search is mobile. So search results are weighted on this.
Mobile websites are given a higher priority than regular sites so your Mobile Website has a better chance of appearing much higher in search results.
Chances are your regular website will not perform and appear correctly on a mobile device.
Regular websites appear very small and difficult to navigate. A lot of functions that normally work will not do so on a mobile phone.
By having a mobile site designed specifically for the Mobile user (remember there are 11 million plus in Australia) the visitor is able to quickly and easily find the information about your business.
Having a Mobile Website not only improves for Mobile Visibility it also improves your visibility on the internet as a whole.
You see Mobile Sites appear in all search results, not just mobile searches.
So getting a Mobile Website can effectively double your Web Presence.