tl/dr: email chains used as evidence in DOJ Google antitrust case show internal arguments about drops in # of searches, and how to increase them so that people see more ads. Search team wants to create better search results to keep people coming back.

Advertising team wants to find any way to make people search for as long and as often as possible (“increasing the journey length”) even if it means delivering less relevant search results.

You can actually read many of the trial documents here -
https://www.justice.gov/atr/us-and-plaintiff-states-v-google-llc-2020-trial-exhibits

this file was particularly interesting. https://www.justice.gov/d9/2023-11/417557.pdf