One of my favorite stories to tell is when I was looking for a bicycle to buy. I love buying local and supporting my local economy---I've always viewed it as a mission to support my local small businesses even before it was fashionable to do so.
I was having difficulty finding the particular bicycle that I needed and ended up doing an internet search. I went to another state to make the purchase because there were no businesses listed with the brand that I wanted locally. It is important to have the word out on your business in various ways on the internet otherwise your customers could be going to the next state over and passing you up.
On the mobile site you can add monthly/weekly deals, product photos, events, and hours. It is a handy (and handsome) website widget that can help your customer and can even be easily emailed to friends or shared to Twitter and Facebook.
To contact you by phone the customer simply hits the button. This is how the mobile web was designed to work---easy and fast, with a "meet you at the store or event" sharing ease of use.