Quote Originally Posted by xelement5x View Post
All trolling aside my theory was that the spike in Earthbound sales was due to the release of Smash Brothers Brawl (March 9, 2008 in NA according to wiki) and the inclusions of Ness in that game.

Brawl was an extremely popular game on an extremely popular console, and Ness could be considered an "unknown" to many people compared to the likes of Mario, Link and Kirby. Players wonder about the "unknown" character and the game he's from and want to buy the game, demand can't keep up and prices spike and continue to stay artificially high even though there was a decent number of copies of the game produced.
It's not really a theory at this point. It's pretty much fact that Smash Bros. boosts the popularity of the lesser-known characters/games. The new Kid Icarus owes its existence to Smash Bros., and prior to Marth and Roy being included in Smash Bros., practically no one in the US cared about Fire Emblem. Now we've gotten nearly every (maybe all?) Fire Emblem games since then. Pikmin also had a surge from Olimar's inclusion.