Excerpted from (link) BUZZ article:
"Although fictional, Festivus satisfies a longing for a noncommercial alternative in the Yuletide season, and has inspired parties, searches for cards, pole purchases, and look-ups into its traditions. Those include the Airing of Grievances (when people gripe about the year's disappointments) and Feats of Strength (the head of household wrestles with whomever he or she wants). A Festivus miracle is the opposite of what a person wants.The holiday may not have carols or decorative trees, but it's got a pole."