Off course you dont. I have seen the clever hacks with side effects. :-) And if you have a night flight duffle- why would you put things anywhere else? My Pilot stays with me all the time with everything close by.
In the last month I have saved 3 people from forgetting things in the seat pocket. 1 ipad. Stressed businessman. 1 ipad and a coat on the hanger in the middle seat. Even more stressed businessman. The third was a young woman that forgot her passport and her boardingcard for her next flight. I can understand her. She was stressed because our flight was late in and her connection to Moscow was really tight. She was running up the aile without her passport before I stopped her.
So my tip is: Even if you are not a stressed businessman- never ever ever ever put anything valuable in the seat pocket.