This is because electronic cigarettes contains only nicotine, and some taste enhancing substances. However, it does not have other poisonous substances like arsenic, formaldehyde and most carcinogens that are present in normal cigarettes, which can have the effect of blocking your arteries and lungs while smoking.
An additional and important benefit of smoking an electronic cigarette is that it is completely legal because of its lack of tobacco. This makes it possible for you to smoke it wherever and whenever you want. The electronic cigarette is also odourless, meaning that you will not have that lingering cigarette smell on your clothes after smoking it.
It is this absence of odour and harmful vapour being emitted into the atmosphere this makes it possible for you to smoke this electronic cigarette in public instead of hiding and smoking. In addition to this, you no longer have to worry about your smoking being harmful to the others around you.