As you can see from the short list provided above, when you have your Google analytics account setup for your website these will be some of the types of stats you will receive about your visitors on your website. Having a website alone and not knowing who is looking at it or where they are looking from has no advantages. With Google analytics you can measure differences between different ad campaigns you may decide to have.
If your company is based in Cape Town and you would like to advertise in Durban, you can now see the impact of the advertising by setting data dates to the start and end of your advertising campaign. By subtracting your actual visitors on your website during the campaign by the total targeted audience, you can measure the success of you advertising. The advantages of this allow you to measure various campaigns against each other and to optimize individual campaigns.