When you buy a bottle of water, you know exactly what you pay for it. You might buy them in bulk, thereby making your per bottle cost cheaper, or you might buy a single bottle from a vending machine for a buck. You can rest assured that it will be safe, and effective in quenching your thirst. What makes you come to this conclusion? You have done it before, and you have seen others do it before, successfully. You know what taste to expect from each particular brand (Aquafina wins hands down in my opinion). Whether you are in California, New York or Mumbai a bottle of Aquafina still tastes just as good. Can any of you "tap water" drinkers make the same claim? I think not. In fact a cup in Mumbai could kill you, and one in Cali could make you gag.
Lets take a look at this insidious species known as "tap water." Where does it come from? You think it comes from a local public reservoir, but it's truly a mystery. Whereas with Aquafina you can verify the process by which it's made online, by way of a nice graphical presentation. With "tap water", you must hope that the local government isn't corrupted into adding chlorine or a number of other potentially toxic substances. If Aquafina does this, you can sue or boycott them and take away the livelihood of their shareholders and employees. With "tap water", you must wait for the next election to change the system. You must hope that improvement of "tap water" is somewhere in the packages of promises made by various self-interested politicians.
You "tap water" drinkers make the ridiculous claim that it is "free", and to drink bottled water is a waste of resources. Do not kid yourself that it is free. You are paying for it through the mysterious phenomenon known as TAXES. What is the price you pay? It is not easily determined, as each inefficient government institution involved in its creation will add a not-insignificant cost.
Most of all, bottled water proves that the Free Market can handle with excellence even the most basic essentials of life (a concept that escapes most of you "tap water" drinkers). If you want a truly efficient system to distribute any resource at any time and of any kind, the Free Market is infinitely and eternally superior to government institutions.