In laymens term what does the 3g get me? Why do I need this? I'm asking because I picked up an Ipad for my daughter yesterday and thought I picked the basic model. After I got home I looked at the receipt and realized they gave me the 3G model. Is it that I need to pay for an additional data plan on the 3G? What does the data plan get me that regular wifi connection at a hotspot, or here at home doesn't?