In this Dilbert comic strip from 09/27/2015...
(Strip source: http://dilbert.com/strip/2015-09-27)
...the C.E.O. says in the last square:
I just need buy-in for the strategy
What does "buy-in" mean in this context and why is it used here (i.e. is it a case of using a term that is normally used in some similar but different context)?