Practical implication: If you are stranded on a desert island and you attempt to solicit a rescue by releasing a message in a bottle, you have about a 65% chance of a response (within ten years, I guess). In order to get that above 95%, you would need to release 3 or more bottles. 5 bottles gets you a 99.5% chance.

Of course, you'd better have a GPS device so that you can write down your coordinates on the message, or else you'd better hope the bottle turns up at an oceanography instutute that can trace the ocean currents back to where you're stranded.