Electronic Cigarette to quit smoking

My cousins got them as gifts last Christmas. They do not seem to understand that you have to step down the nicotine content....

They are nothing but a vapourized nicotine solution. While the nicotine is just as harmful the user is not inhaling the tar, glue, and other carcinogens involved with smoking tobacco. What makes the electronic cigarette valuable for quitting is the fact that you can gradually step down the nicotine content. Many clinical trials have shown that a gradual lessening is far more effective than going cold turkey in the breaking of an addiction.

Where's the data on how much nicotine someone inhales?

I have not read any clinical trials on nicotine consumption and the e-cigarettes. I speak only anecdotally, as the versions my cousins bought have a selector that allows them to control how much nicotine they get with each puff.

Before anyone thinks there's an inconsistency with how my cousins received them let me say that their mother have them the money to but them specifically as their present.

Also before you point out that I mentioned clinical trials that was in regards to reducing addiction not in regards to nicotine itself.