What is “Ad Maturing”? (How 48 Hours of Patience Lowered my Facebook Ad Cost by 34%)

https://www.youtube.com/watch?v=9hu3pLI5asg&t=612s&ab_channel=DmitryPuchkov&clickid=lqhjpft1jsppi2jiq8j3buhpubatiqshlk2errji3fs1njjfu9mj2jpi1bpjdi801g_2079511689