to quote: 'I can't imagine what they're doing during that maintenance window.'
Like lottery houses, they shut down to offload all gaming mined data into number crunching statistical analysers, to make sure their winnings are tweaked and calculate the 'worst' possible payouts to ticket holders (all gamers), and tweak auction house item stats accordingly. It's probably a very complicated algorithm analyser powered by Google, I'm sure half of the development cycle was based on formulating all this, and then some.
the house always wins.