Multivariate Testing for Marketers

I was surprised to learn that according to executive surveys conducted by JupiterResearch, only 24% of companies are currently using multivariate testing when evaluating their websites effectiveness. 

It certainly seems like low hanging fruit even a 2% improvement in conversion rates could mean millions in incremental revenues.  The value of multivariate testing is to yield improved conversion results.  In some cases swapping out a photo, message, and/or offer can make a huge difference. So why are so many companies hesitant to start using multivariate testing tools?  According to the survey, the biggest concern from executives is how to recognize ROI with testing.  Below is a graph showing the top roadblocks to implementing multivariate testing programs:  Our interactive marketers at WebsiteBiz are experts in multivariate testing.  We primarily use Omniture Test & Target (previously Offermatica) and Google Optimizer depending on the complexity of the test and requirements.  As marketers have you found similar resistance from executives?