The concept of swapping flavours immediately is brilliant. But there are a few flaws. I find that the vapour density decreases after a few puffs, the experience is not consistent through each ePen cap. Also, it seems the batteries don't have a substantial operational life. I purchased my ePen in January and by April I had noticed a distinct lack in quality. When I purchased a new ePen the difference was remarkable. The mouth peice cracks where it connects to the power unit after prolonged use. Also the metal connection plate corroded and became tarnished after a few weeks of use. The price of the ePen compared to smoking is considerably lower and this is its saving grace. I think if the aforementioned flaws were corrected or improved upon, you could charge more per unit. People pay for quality and I believe the concept has the potential to be the leading brand in the industry. My thanks, Allan Redding Im contactable at allan.redding@gmail.com if I can help or advise anything further.