These discs are physically distributed to Best Buy Magnolia Design Centers, audio dealers, and Dolby’s partner studios. They are . Consequently, the "download" scene thrives on P2P sharing and enthusiast preservation.
The most reliable way to obtain official demo material is through Dolby’s own support channels. Dolby Atmos Demo Disc Download
The "story" of the disc is often told through its iconic trailers: These discs are physically distributed to Best Buy