I play on three for a couple of reasons:

1. Because I think that nearly all the records I play sound better mixed with another. So, if i'm playing on two it sounds great but then I have to take one out to get the next on...which isn't what I want to do.

2. When you first start mixing it's a challenge. And that, alongside playing music I like is the reason why I spent a lot of time doing it. Playing on two is no longer a challenge and is very routine. When I started to play on three it gave me that challenge back again.

As said before if you turn up for a gig and the monitoring is so shit that you can't hear anything then playing on three is pretty much pointless. Nothing is more annoying than that. I sometimes can't belive how little effort promoters put into getting the set up to a reasonable standard.

I would also agree with other posts saying that some djs do say they play on three but don't really (or at all). Maybe they think it will make people think they're better? Especially when you see flyers that say "on 3 decks" next to the djs name. Although that's usually down to the promoter.