If the only incentives Colorado offers are tax breaks on wages then that's essentially what will happen.  Only instead of Amazon paying full price to move here they will pay half price.  Either way they will bring more economic development than they will get in tax breaks.

Which is the perfect way for Colorado to go about it.  Having a huge and growing company move here would be great for the State as long as it isn't a net loss for taxpayers.  Since Amazon will only get tax breaks based on the number and salaries of the people they hire the State is projected from them just taking State money and moving on.  Or if they don't expand as much or as fast as they originally thought Colorado isn't stuck with a huge upfront bill.