The T.V. ratings and social media engagement on ESPN may be down in recent years but there is no question that when ESPN releases a preseason ranking people pay attention; the kind of people who vote in the AP rankings.
The AP rankings are what sets the bar until the BCS rankings are released just past the midway point of the season. The BCS rankings although heavily influenced by computer there is still a human influence that determines who is number one and how good a schedule/opponent is.
Sometimes this plays in favor of teams such as in 1984 when BYU took down then No.