2014 could be the make or break year for electronic cigarettes.
The tobacco industry plans to ramp up marketing next year and challenge opponents with its contention that "vaping" can save millions of lives.
Eventually, tobacco companies sees sales from e-cigs surpassing sales derived from traditional cigarettes.
What to watch: The U.S. accounts for 25% of global sales and is integral to the future of the e-cig industry? Will a recent ban in New York City influence other regions?