I cracked the "wall" today - ~.95 ecpc, absolutely insane amount of conversions I have never seen money come in so fast in my entire life... I guess this IS real after all..
Is this kind of up and down thing to be expected? I am brand spanking new and not quite sure what to make of it all yet...
You have to find what works and then spend more time expanding those areas. It does not take a lot of money to effectively test something, so be careful with going overboard until you get a feel if something has any potential.