I need help understanding something.

at current lower end rates of 0.015 btc/mhash/day.. renting rig out still yelds 1.5-2x more value than mining at most pools, including some of my favourite ones... I really don't get the economics of renting.. I mean, I'm loving it, but I don't get what makes it profitable to the renter?? I.e...  Ican't find a pool that would pay me more then I'd get for leasing my rig out.. even with altcoins and coin switching. etc.