"Apparently the word 'because' signals reasonableness, and reasonableness allows people to let down their defenses and drop their objections. If the science is accurate, an effective way to ask for money might look something like this: 'May I borrow a hundred dollars, because I don’t get paid until next week?' That’s not much of a justification for borrowing money; no real reason is given. The person asking for money hasn’t even said why he needs it. It just feels as if a reason had been offered because of 'because.' I’ve tested this technique and it works surprisingly well."
From Scott Adams, "How to Fail at Almost Everything and Still Win Big: Kind of the Story of My Life" (citing studies by psychologist Robert Cialdini).