E-Cigarettes: Did you quit smoking using these?

Here is another interesting study that emerged from the American Thoracic Society Conference in Denver this week: http://www.dailymail.co.uk/health/article-3087507/E-cigarettes-DON-T-help-smokers-quit-long-term.html

The study found that e-cigarettes help long term smokers quit within one month. However, longer use (3-6 months) of e-cigarettes has users taking up tobacco again.

What do you think? Do you use e-cigarettes? Did they help you quit smoking? How long did you use these before quitting?