Why are costco and sams club always adjacent?

Question

why do costco and sams always end up next to each other?

are they competing that hard?

Answer 1

Costco's direct competition is Sam's club.  But that is because they are both membership clubs.  

There are 50 costco warehouses in Northern California and there are 10 that are close by a Sam's club.  

So 1/5th.....

Answer 2

They aren't in my town.

Answer 3

Not always..

I have a Costco membership and there aren't any Sam Clubs near the ones I go to.

Answer 4

I've been working at costco for years and I've never seen a costco and a sam's be anywhere near each other