http://www.bonethefish.com/viewtopics.php?2139

iCarly is a television series, which premiered on September 8, 2007 on Nickelodeon. The series stars Miranda Cosgrove, Jennette McCurdy, Nathan Kress and Jerry Trainor. The series is created and executive produced by Dan Schneider. The series focuses on a girl named Carly who creates her own web show called iCarly with her best friends Sam and Freddie.

I didn't care for Gibby joining the main cast and it was definitely running out of steam with all of the specials and guest stars.

But I can't say it actually Jumped the Shark.