Why footer score is low despite the last paragraph being the peak:
The Slot Scores function calculates scores using two things:
- The scroll depth multiplier
- The footer zone
The footer zone only covers the last few paragraphs. Even if the last paragraph is the peak individual paragraph, the mid-zone can cover much more paragraphs, so mid_sum likely far outweighs footer_sum. The scores are relative — footer_sum / max_sum * 100 — so if mid has 9× more paragraphs accumulating time, footer gets a very low ratio.
The last paragraph being the “peak paragraph” means visitors who did scroll to the end spent the most time there (possibly a conclusion/summary). But on average only a certain % of people scroll far enough for a footer ad to be viewable, hence the low score. The footer being hidden is correct behavior — placing an ad where most of the visitors never reach it is a poor placement.