Well, I'm a bit late to the party on this one but here's for nothing:

If you have a different configuration of a software (example: you want one build with a help file included and one without), you can use releases, in short, take the following actions:

1) Define releases using the releases visualizer
2) In script editor surround the things you want specific to a particular release with #ifcompvar and #end directives thus something like

#ifcompvar [sb_releaseid] = "fullver"
install file(s) somefile.chm
This basically says that if you compile a release called fullver, then the help file will be installed, else it won't. if you just click the compile button it compiles with the settings not overridden by a release, selecting the drop-down menu next to compile will allow you to choose a release to build.

Basically think of releases as the build-time equivalent to features. Features act as limiting agents at install time (the features selected by the user dictate (or limit) what files and actions are taken at install time), releases act as limiting agents at installer build time (the files and action items specified by the release are compiled into the output file and nothing else thus they filter (or limit) what the final install can do)

I'm sure you could think of another way to use releases but that's the use I've found for them in a current project of mine.

Hope this little bit of newly-discovered knowledge helps someone. For more information on releases, check out the help topic on the subject on the SetupBuilder help or the PDF manual as this is my at-present limited knowledge of releases.