You can use groups to bundle all campaigns for a particular book. You may use different ad campaigns – Product Display and Sponsored Products – for one book. You may also have different campaigns – using keywords to target more than one market – for one book. When you group them together you can see the summary of these campaigns.
You can also use groups to track a book series or compare a single book to a book series. By using groups you can easily track your summary on sales and ad spending.