Purchasing the track via iTunes or 7digital ensures you own a high-bitrate file (256kbps AAC or 320kbps MP3) that supports the artist directly.
Yes, this song was engineered by Grammy-winning mixer Colin Elliot . To appreciate the dynamics—the quiet verses exploding into the loud rock chorus—you need 320kbps or FLAC. Streaming via Spotify on "Very High" setting is equivalent to 320kbps, but downloading the MP3 gives you control forever.
While MP3 is a "lossy" format (it discards audio data deemed less audible to the human ear), a 320kbps MP3 is often indistinguishable from a CD source for the vast majority of listeners. The search query indicates a user who is discerning enough to reject low-quality streaming artifacts but perhaps lacks the storage space or hardware support for FLAC files, or simply prefers the universal compatibility of the MP3 container.