To TrippH
What ever you do -- make sure your prefilled carts have good flavor and are not nasty. Otherwise you will lose customers.
You could have 3ml MEDIUM nic juices for sale, flavors for DYI, some PG, and VG. Find a supplier that could mix all of this for you in a CLEAN environment. Check out the laws in your state about "food grade/kosher" handling of saleable items. (not sure how to word that).
Also you might want to put some type of
ecig advertising posters in local bars, dance clubs, gas stations, etc.. to help generate new customers.