
click to enlarge
The information provided to you on these reports is of great use to you because it helps you decide where and what sort of changes need to be made across your site content.
By using the navigation analysis seen on the left, you will be able to tell how each visitor gets to your content. If you look at this factor on the pages you have targeted for advertising, you will be able

click to enlarge
to judge how well certain advertising campaigns are doing in not only bringing people to your site, but how people are responding to the ads. These are good reports to use in conjunction with the Traffic reports to track your campaigns.
By using the landing page optimization seen on the right, you will be able to better judge the keywords that you should be using to try to rank in the search engines and earn traffic. It will help you in keeping information relevant to your target audience so as to keep them on the page long enough to get them interested in other content, and prehaps making a purchase if purchases are your goal.
The important thing to remember is, regardless of the results that you are seeing, you should analyze and discuss ways to make them better. You should always try your solutions on a trial and error basis so as not to completley alienate and upset the exisiting traffic base that you have. It will take time, patience and maybe even some user studies, but it can be done.