It's not solely applied to Stevie and Lindsey "shippers":
http://en.wikipedia.org/wiki/Shipping_(fandom)
However, the archives of the newsgroup X-files show that the word "shipper" was already in established use among fans of The X-Files as early as May 1996 [1]— just three months after the first Pokémon games were released in Japan.
The TRUTH is out there.
