It is a few things.
One big one is that many of these companies mine with the gear they pre-sold before they ship it out thus making a double profit.
Also there are tons of companies shipping gear or that have recently shipping gear out. Ant MinerS1's went out in droves over the last few weeks and have been getting deployed.
Also several hosting centers that have been busily building for months have now starting bring their farms online.
There has been a huge amount of hash coming on line recently.
Ok so the numbers from the pools are wrong, but can anyone explain how the network hash rate is increasing so rapidly when no ASIC companies are shipping new equipment right now?