Beer Kegerator

Come buy a Kegerator (beer tapper that is attached to a mini-fridge, which houses a half-barrel) and I have a question about it ... how long the barrel last time he tapped? How long until it goes wrong? Is life different from one half-barrel of a quarter barrel?

Help appreciated

Keep it Nice and chilled and it should last a few weeks or so, unless you drink it. Life does not change because you are not aging, it would be different if you were good.