Not likely that a ton of folks bought their e-cigs there anyway, many go through local tobacco shops. But still a huge step for the world's largest retailer.
There are many factors here. What is the effect of 'additional' substances or 'flavorings' that may be added to the vape inhalation process? Are people using 'black market' or off market devices?
Most stores won't sell an obviously 14 or 15-year-old an e-cig. But surprisingly, the industry has largely been unregulated since the popularity of the electronic smoking devices has exploded a couple of years ago. Now, get ready for a heavy dose of state regulations.