You can view ad campaign reports after your ads start displaying. Click on View statistics on the campaign page. If you check these statistics regularly, you will know how well your ads are performing to bring users to your site.
You can get detailed statistics on all your campaigns and evaluate the effectiveness of specific keywords and ads by using the Report Wizard.
For example, you can see what sizes of creatives are displayed most frequently for image ads. To see this, go to Cross sections and select Ad № and Image size. In Columns, select Impressions. Then add the filter . Statistics show that image ads with creative sizes 640×100, 640×200, 640×960, and 960×640 (in pixels) display as 320×50, 320×100, 320×480 and 480×320, respectively.
Read more information about campaign statistics.