I only have a minute but.. in McLeod's case, he took it from being a mere hobby of scribbling on the back of business cards, through to refining the concept of the "social object" and, more recently, the "cube grenade." Going into what this is all about is a bit much here but this might help: http://gapingvoid.com/2007/10/24/more-thoughts-on-social-obj... - Crucially, though, his art is specifically focused on business and is primarily sold within a business context - no galleries, often used for offices, etc.

Hirst.. you could talk about for hours and go round in circles, but if you follow him for a bit you'll see a very savvy business mind at work. Not many artists have a couple hundred million dollars in their bank accounts. It's not a cynical money grab though; he's got some great ideas going on.