Something to remember if you are new to the whole electronic cigarette concept:

E liquids now have low nicotine

The electronic cigarette sees many new developments in short periods and the phenomenon of ever-increasing low nicotine eliquids is one of them. Electronic cigarette users were definitely not vaping with 1.5mg or 3mg liquids 3-4 years ago, it was all pretty much 9mg and up. But sub ohming changed all that. As resistance values dropped, nicotine levels dropped. This is because when you vape sub ohm, nicotine feels much harsher (talk about a real throat kick - 0.2 ohms, cranking 200W with 24mg nicotine juice lung hit). A vaper who normally vapes 9mg liquid might sub ohm at 3mg or 6mg or some similar level, but it will definitely be lower. Sub ohm vaping has been the overriding factor which recently affected the massive growth of low-nicotine eliquids in the last couple of years.