A few years ago Who Wants to Be a Millionaire premiered as the first nighttime game show in a couple of decades. Once the show became a hit and televised several nights a week, other networks quickly created their own version of what they hoped to be a successful game show format. Greed and Twenty-One are the names of but two of the new shows that were created to compete with Who Wants to Be a Millionaire. 

At this point in time the nighttime televised game show genre entered which stage of its product life cycle?