Don't give it to them all at once, make them work for....

“ Don't give it to them all at once, make them work for it. Confuse them with detail, leave things out, go back on your tracks. Be testy, be cussed, be difficult. Drink like a fish; don't give way on the ideology, they won't trust that. They want to deal with a man they've bought; they want the clash of opposites, Alec, not some half-cock convert. ”

John le Carré

From : The Spy Who Came In from the Cold