I first came to PP because I was researching concert dates for bands I like, that I had never seen live, many of whom rarely come to the US. And one year I came across four that were going to be playing on Atlanta on the same day, what a strange coincidence.
Those four were:
Fates Warning
Circus Maximus
Pagan's Mind
Brainstorm
And the next year we added to the list another two bands that I wanted to see for a long time but thought I might never get the chance:
Leaves' Eyes
Tarot
Ok, that's six, but the point is this is why I'm so thankful that PP exists - being able to see bands that rarely, if ever, tour the US or may not come near me. Putting all that music in one place in a couple of days makes it somewhat more cost effective rather than flying all over the place to see a bunch of different artists.