In the days of yore, continues and lives were a staple of the medium of video games and practically inseparable from arcade games. And why not when you were trying to get the most quarters out of players - you needed to limit the amount of play time and thus the law of the day was lives being a precious resource only extended by continues... for a price. And when people demanded the arcade experience at home the lives and continues went hand-in-hand. Besides, these were early days and the hardware was quite limited: having players starting over from the beginning of a stage or game was a perfectly practical way of making sure they got a lot of play hours out of their home video game purchases.
But not anymore. Not only has this style of gameplay been superseded, but players expect to play their games for a large number of hours in sprawling games environments. So why do we still have limited lives yet unlimited continues? In effect, that is unlimited lives. It is like the coins and other collectibles in a modern platformer like Mario - sure you could get enough of them to earn a 1UP, but why when you can just continue and get a small stockpile of lives instead?
So lives, continues, 1UPs, mans - drop them or keep them? When and where?