About 48% of the country lives in the Eastern time zone; 30% in the Central time zone. By 10:15 or 10:30 PM sports fans are finalizing their day and getting ready for bed. They are not staying up til 1:30 AM to watch a game. You are talking about time slots where only 22% of the population is inclined to watch a whole game while 78% is likely to go to bed at the half. The audience reach decreases throughout the game. If it is on at all in the EST or CST timezone, it is on at bars or restaurants and those present are probably drunk and tired. Common sense tells you advertisers are not paying premium prices for ad time (like they would for primetime) because the impact of those ads is less effective and has a more limited reach. A network is not paying a conference premium fees that eat up smaller amounts of ad revenues. These are purely content fillers and likely loss leaders or lower margin content. ESPN doesn’t get a charitable deduction for paying the PAC more, so there is nothing in it for them.