Complex sentence: Realizing that people were eager to purchase the discount pizza's it was decided to do on Mondays and first introduced as Monday Madness the craze took off bringing the store out of the red and into the black.
Split into simpler sentences: Realizing that people were eager to purchase the discount pizzas, it was decided to offer them on Mondays. First introduced as Monday Madness, the craze took off, bringing the store out of the red and into the black.