Can you subtract the amount of Money that you've spent on your eCigs. They're not free, that's for sure. I think that I've only saved about half as much as the counter says, maybe less.
The vape banner takes into account the amount you spend on e-cigs. It basically works how much you would have spent on cigs, then deducts the cost of what you have spent on e-cigs to work out your 'savings'. All the figures are configurable. Take a look for my recent post on the next version of the vape banner!
My banners don't ask for your email address, or any personal information. The only stuff recorded is what you enter, and your IP address. The only danger with my banner is that at some point in the future I could replace the images returned with an advert for my site, or some other dodgy site

However, I think we can all imagine the impact on my e-cig business if I did that, not to mention I would be banned from every e-cig site on the planet!