Target based on the position of the Ad on the page when a viewer first encounters it. Harking back to the newspaper industry, the industry terms "Ads that are immediately visible" as "above the fold", whereas those that require scrolling or other interactions before they may be viewed are termed "below the fold".
1-Select Fold from the Pre-Bid Targeting pop-up in the DSP
2-Click Include if you wish to target particular Ad positions. Select Exclude if you prefer to anti-target particular Ad placements
3-Check the boxes of the Fold Placements you wish to target, or anti-target. Naturally "Above the Fold" positions tend to receive more bids, but also tend to cost more
4-Click Save & Close when complete
Depending on the Exchange, there may be cases where the Ad position is not reported to Zeta; these cases are classified as Unknown. Checking the Unknown box permits the DSP AI to utilize these placements and helps in finding enough opportunities to display the campaign's Ads.