This is the story of a scam … probably. It is, if nothing else, the story of one inexplicably successful Bulgarian Spotify playlist.

As Music Business Worldwide reported earlier this week, multiple music industry insiders say a random playlist managed to siphon off what may well have been millions of dollars in Spotify’s pool to pay artists’ royalties — all potentially without breaking any of the site’s rules.

The alleged scam is the perfect mix of absurd and audacious. An individual or group in Bulgaria created a couple playlists, unimaginatively titled “Soulful Music” and “Music From the Heart.” The more successful of these, “Soulful Music,” was at its peak as the 35th most popular playlist in the world and the 11th biggest in the United States, even though it had a measly 1,797 followers and only about 1,200 monthly listeners.

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Music Business Worldwide’s story explains how the moneymaking trick worked. “Soulful Music” had 467 songs by virtually unknown artists — which is to say, artists who may have been created for the purpose of this alleged scheme. The vast majority of songs were about 30 seconds long, which is the minimum length a song needs to be to count as a monetized play on the service.

The most probabl explanation for all this is that someone or someones in Bulgaria set up 1,200 computers with premium Spotify accounts, then had them play the songs on “Soulful Music” constantly. While it would cost $12,000 to set up all those accounts, the payoff would be worth it.

The report estimates it would be possible to squeeze out at least 72 million plays of the songs out of those 1,200 accounts, which would be the equivalent of $288,000 each month. A little finagling of the playlists so each song played for the bare minimum of 30 seconds could up that number to north of 100 million plays, or about $415,000.

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Technically speaking, none of this violated Spotify’s rules, assuming the people behind it paid for all those premium accounts legitimately. But it’s not a victimless crime, either, as this would have cut into the total royalties Spotify had available each month to pay actual artists and creators.

What’s most embarrassing, as Music Business Worldwide points out, is that this went on for months, with these playlists working their way steadily to the top of the confidential playlist chart reports before anyone at Spotify or the music industry realized what was even going on. The scheme appeared to reach its zenith in the summer of last year and went undetected until October 2017.