It could prove beneficial some times. I was playing a 1$ SNG one day, and i remember reaching the final table, and boom the chipleader just goes on "sit out". Funny thing, in just a few hands, i find myself heads-up with the guy, and just bled him dry until i won first place. Now, as a matter of tactics, it's something as old as the game itself, and maybe/probably the guy was happy with 2nd place, since we all know how things can spin around in seconds. Then again i just think he had an emergency, and had to step out.