one person heard the numbers and thought that they were bad luck and killed himself eventually. Hurleys friend went crazy. Hurleys won millions and thought all his bad luck was caused by them. but survivors are numbered on Jacobs wall and the lighthouse wheel and as far as I can tell they were ordered with the numbers and they are still alive.
- The numbers are somehow tied into the fabric of the Lost Universe. They are both/neither good or bad luck. Hurley won millions (and kept winning millions) after using them - good luck. However on the flip side bad luck things kept happening to everyone around him.
- Referring to the above point: The numbers are supposed to be variables that describe the "human and environmental factors", or in other words, the state of the world. They are used in the Valenzetti equation to predict the amount of time before mankind extinguishes itself. The purpose of the Dharma Initiative was to try to change any one of these numbers to change the date of doomsday.
I think that Jacob used the numbers to control the Losties destinies.