Firstly the Double Click Ad Planner is online tool that can help you improve your online marketing efforts by identifying websites your target customers are likely to visit and then build on this by creating media plans. Once in the tool within the research tab you can search by site or by audience.
Within the search by site you are able to enter URL’s for sites you would like to advertise on and view detailed traffic statistics, statistics on the demographics of visitors (such as age, gender, household income), keywords searched for as well as information on ad placements such as the number of impressions received per day. If you want to understand which sites will give you the greatest exposure you can use the search by audience tab where you can apply filters to identify sites that are frequented by your target audience. Once this is done you create a media plan and can add the sites that are most effective at targeting your audience and implement this in Google Adwords or any other PPC provider.