its hard to tell, they have krave, which is in dollar stores. probably single digits for the cig-a-like market
the tank market is half of the entire e-cig market, but cannot be tracked because it isn't sold in convenience stores. that is the growing market and it is kindof going off the trackable grid. read article, that is why the article is saying "sales shrunk"
Last time I had estimates and financials, and did the math, I had them pegged at about 3-5% but that was a while ago, so I have no idea anymore, but I imagine it could be similar. It may sound small, but a few % points of a multi billion market is pretty decent.