You've likewise heard all the speculation and theories as to why some One Hit Wonders who stole our hearts and minds (and sometimes even libidos) during that special one-time breakout limited-time offer of theirs weren't able to become Two Hit Wonders, or Threepeats, or so on...
"It was just a fluke."
"They were in the right place in the right time... once."
"They just didn't have any staying power."
"They were a one-trick pony."
"They were consumed by fame, drugs, cockiness, significant others, etc...."
This nigh-review article looks back at three webcomics -- Brambletown, Nowhere Girl, and Piercing -- that blew our minds, then blew out of town.