I did.
I'd been made redundant, packed the kids off to school one morning, bought a pack of 20 cigs, realised I'd finished the pack just before they came home!
Bought a Blu ecig the next day. Haven't bought cigarettes since, or blagged one off anyone else.
What also helped was setting up a spread sheet with what I would have spent on fags and what I was spending on the ecig, and calculating the difference in spend. That was a shock after a month or so.