http://www.youtube.com/watch?v=Z0VHJ1_tAOQ
Watch this video.
She says, if you don't have much hair, it is attached with medical tape. So its basically a piece!
Then she says if you have more you it is attached to the individual strand of hair... so its a hair extension!
Then she starts to refer to it as a system!
Then she finally gets to the real video.
Hair integration is just a fancy way of having your piece weaved or sewn into existing hair.
I'm sure its fine if you are a woman and have long hair, but for a guy with short hair, when you tried to comb it or gel it, you'd mess up the knotting.
Plus, having that knotting done really ruins your existing hair. For a woman who has chemotherapy, or a woman who has some balding in certain areas, its fine. But definitely not good for a guy, unless you have want to have long hair.