That's true. I attended a somewhat notable music festival this year and I noticed that the bands on the line-up had all the other bands from the same festival

That's true. I attended a somewhat notable music festival this year and I noticed that the bands on the line-up had all the other bands from the same festival in the "similar" section, despite not being similar at all - (I'm assuming) just because other people interested in the festival were checking them out.