"There is no such thing as bad publicity except your own obituary"

In this quote, Brendan Behan is suggesting that any kind of promotion, even if it is unfavorable, can be advantageous other than for when it is your own obituary. This means that any sort of attention or direct exposure, whether it is great or bad, can still bring some sort of benefit or advantage. However, when it concerns your own obituary, it is the end of your life and there is no other way to turn that into something favorable. This quote highlights the importance of maintaining an excellent reputation and preventing negative promotion, as it can have a lasting effect even after death.