Years ago, I read Automating the Build Process at Gamasutra, which documented an automated build process for the game Creatures 3. The advantages for implementing an automated build process include better reliability, reduced time, and reduced risk.
A few weeks ago, a new article has appeared called
Automated Build and Test Systems for Games, which outlines what Nihilistic Software does when developing their own games. Once again, time savings are emphasized.
In both articles, it seemed that some customization was needed, but you should be able to find a way to automate the process for your own games. One tool I found is BuildBot, which mentions among its users id, which uses it for Return to Castle Wolfenstein: Enemy Territory.
The overall goal is to reduce tree breakage and provide a platform to run tests or code-quality checks that are too annoying or pedantic for any human to waste their time with. Developers get immediate (and potentially public) feedback about their changes, encouraging them to be more careful about testing before checkin.
Any time you can use a computer to automate a repetitive task, you’ll find consistency in quality and speed as well as fewer headaches related to the meta-work of making a game. While I believe that having it automatically build everytime a change is made would be overkill for a one-indie shop, having it delegated to a button-press would definitely help.