In a plain folder where each revision gets its own subfolder named as the revision number? That, yes. What's the point of versioning a build? After it's built

In a plain folder where each revision gets its own subfolder named as the revision number? That, yes. What's the point of versioning a build? After it's built, it will never change. Back it up, of course. But don't version it. Automate your build and let it do the checking-out, compiling, testing, tagging, copying, emailing and what not, for all eternity.