The Ghost of RubangB on 17 April 2009
It was cheaper to develop PS1 games, so PS1 got more games, so PS1 had a more diverse library which attracted a more diverse userbase, so more types of games were able to sell. This attracted more developers, which made more games, and the super success spiral began.
There were a few other issues involved, but the cheaper development and cheaper CD's were probably the biggest reasons.
