This phrase seems to be Silicon Valley
slang. Used generally, it refers to believing religiously in the New Economy
; more specifically, it's used to refer to believing your own propaganda
, or that of whoever you're with: You're on the team
, "signed up
", committed to the madness at hand, etc.
I'm guessing that it derives from the LSD
in The Electric Kool-Aid Acid Test
by Tom Wolfe
I've also heard it used, only once, in the Jim Jones
sense of "Kool-Aid
": A VC
who has "drunk the Kool-Aid
" is one who has pumped enough money into your cult that he'll have no choice but to die with you when the time comes. The more I think about it, the more I doubt that this usage differs from the above, except in the sense that the speaker has thought it all through.