The notes in the minor pentatonic scale go so well with blues and most rock music that any idiot (such as me) can produce a musical-sounding improvisation. Just randomly picking out notes in the scale, or going up and down parts of the scale, sounds great on top of the I/IV/V-based progressions that make up so much of modern music. And let me tell you, when you're an at-best "advanced beginner" musician, and you solo for the very first time and something that sounds like music comes out, it feels as good as any sex ever did. My interest in the guitar had been flagging a bit, until a teacher taught me the minor pentatonic scale and gave me the opportunity to play some solos on top of his chords; since then, I've wanted to learn guitar, play guitar, etc. pretty much non-stop.