For those worried about Costco's work in the delivery space

For those worried about Costco's work in the delivery space, it looks like they are making forward progress.  

Howard Mark's book "The Most Important Thing" discusses many good points.  One of his points is that most investors do not consider "second level thinking".  

For example, Amazon bought Whole Foods so the market thinks in terms of the effect of that purchase on other retailers -both e-commerce and bricks and mortar.  This is first level thinking.  Second level thinking considers the reaction of Amazon's competitors.  

As they say in physics "every action has an equal and opposite reaction".