I don't know why you would buy a dvd to learn chip tricks, seeing as youtube has plenty of instruction videos...
I do it because its just something to keep myself entertained while sitting there not doing anything.
Plus some of em, help me count out my chips in a not completely obvious to the other players way.
It's a convenient way to have 6 chips in your hand if your playing something like 3/6 limit too.
And by now shuffling, knuckle rolling, twirling, and butterfly have all become habits when I'm not paying attention, so when I find my self completely bored at the table, I've been trying to learn em all left handed.