Optimology is the name of a religion that serves as a public front for the Order of the Blessed Agonies whose only stated purpose is to raise money for the order's machinations. According to a readable pamphlet at the beginning of 6 Days a Sacrifice, Optimology is an amalgamation of all of the "best parts" of every known religion to date. It is later revealed that the religion has gained significant popularity, as Janine Orzechowski states her reason for investigating the Optimology complex in which 6 Days a Sacrifice takes place is because several celebrities have made the religion their own.
Trivia
Yahtzee based the cults front on the Scientology religion, hugely popular with real life celebrities.