Originally Posted by UAFAM

On most domestic flights (737 and A320s), non-rev passengers are typically assigned seats in 21B, 21E, or 20B, 20E. Lately, I've been avoiding selecting window or aisle seats in the exit row because I know for sure that the gate agent will assign a non-rev to sit next to me, even though the middle seats in all the other Economy Plus rows in front of me are left empty.
Often, there are even window/aisle seats available in the economy cabin beyond row 21, but the gate agents continue to place non-revs in the exit row middle seats.