On this page, you will see a sample layout of how a typical TH Media website is designed. If you look around, you will see how each banner seamlessly fits into each page.
Above, you will see a 728x90 Leaderboard. This leaderboard is designed for top placement CPM campaigns. These ads appear "above the fold".
Over to your right, you will see a 160x600 vertical Skyscraper. These too are designed for top placement CPM campaigns.
If you look down, you will see another 728x90 Leaderboard. Because this bottom banner oftentimes (but not always) appears below the fold, this would be for a CPC campaign.