Bonus Material allows you to make additional media available to anyone who collects your Release.
You can manage Bonus Material on a Release’s settings page. Select a file and write a description of its contents. The description will be visible to anyone, but the file will only be able to be downloaded if a user can verify that they own your Release. Bonus material files are not stored publicly.
When you upload wav files to Nina, they are automatically converted to mp3s for public streaming storage, while the wav are added to bonus material for the release.