The cruiselines already do urge you to leave extra tips in addition to what they've charged to your account. My husband was just fuming after being treated to their little talk which strongly urges everyone to leave more than just the recommended amount which we felt was on the high side anyway. We have no problem with tipping but we do have a problem with being told to tip and how much. We found that although there was already 15% added to our drink orders, the waiters still hung around waiting for an additional tip, which we didn't give because I think 15% is adequate to bring me a drink. This just shows how they encourage even more tipping.