Personally, I consider upfront tipping a form of bribe. We've never experienced anything but top notch service from our butler without it. Besides, they may work harder to earn an extra tip than they would if it were "prepaid." Do note that the automatic gratuity does increase when the stateroom has a butler. That said, for special requests and really exceptional service, many (including ) think it's appropriate to add an additional amount. Just my opinion; others may not agree.