Here's an insane stat: 98.9% of all digital music tracks in existence in 2011 sold fewer than 1,000 copies.

That's 7,931,408 out of 8,020,660 songs.

And 73.9% of all digital music tracks sold fewer than 10 copies in 2011.

The data is from a new book by Harvard Business School Professor Anita Elberse's new book, "Blockbusters: Hit-making, Risk-taking, and the Big Business of Entertainment" (and spotted by Bob Lefsetz).

The data is similar for albums: 58.4% of all albums in existence sold fewer than 100 copies in 2011 — 513,146 out of 878,369.

And 97.1% of all albums available sold fewer than 1,000 copies.

To turn the data around, just 400 separate albums released in 2011 accounted for 35% of all music sales.

For tracks, just 1,514 songs out of 8,020,660 available in 2011 accounted for 40% of all sales.

Elberse comments that the old 80-20 model of the music business, which dictated 80% sales come from just 20% percent of products, has been obliterated.

"For music albums, it is close to an 80/1 rule – if we can speak about a rule at all. Even if we take a conservative estimate of what would be on offer in a bricks-and-mortar store at any given point in time, [predictions] that long-tail sales will rival those in the head are far off."

And all this is even before Spotify took off in the U.S.

And she discusses the implications of these data, for music and entertainment in general:

"what Warner Bros., NBC, and many other entertainment businesses have found out—often the hard way—is that a 'blockbuster strategy' works.

"The leading television networks, film studios, book publishers, music labels, video game publishers, and producers in other sectors of the entertainment industry thrive on making huge investments to acquire, develop, and market concepts with strong hit potential, and they bank on the sales of those to make up for the middling performance of their other content.

"...rather than spreading resources evenly across product lines (which might seem to be the most effective approach when no one knows for sure which products will catch on) and vigorously trying to save costs in an effort to increase profits, betting heavily on likely blockbusters and spending considerably less on the “also rans” is the surest way to lasting success in show business."

Helps explains why you keep hearing and seeing the same big, lumbering songs and movies.