It looks like you inflate as much as you can, and then you roll the little inflation tab in to compress the air and achieve pressure.

By laying on it, you're compressing what's in there, and it pushes back on you. There's no need to ever inflate a mattress like a bicycle tire.

My back hurts just thinking about sleeping on an underinflated mattress. More power to you if it works for you.

The opposite is actually true. I sleep a month a year on a camping pad, and it's well known among avid backpackers that air pads like that shown in the OP are most comfortable when under inflated enough to keep your hips just above the ground.

You still need to achieve some pressure. I find it really unconvincing they didn't show it in use in the video (in one cut).

edit: They will provide proper video apparently http://www.reddit.com/r/shutupandtakemymoney/comments/1eqcbo...

This is not a comment from a hiker. You do need to pressurize sleeping pads. If you're older than 25, you do, trust me.

you'd be surprised how little you need to inflate these types of things to be comfortable. Often times you only fill it 60% or so so it has some give when you lay on it.

Yeah, I was wondering the same. We have some nice fluff about air pressure and moving large volumes of air, but no indication of how any sort of pressure is achieved.