Yes hi I also have this question if I am starting an email based business can I use adsense to monetize my users?
You guys should take a few minutes to read the AdSense Program Policies: https://www.google.com/adsense/support/bin/answer.py?hl=en&answer=48182
but there is a way to get your adsense to someone emails - read it how it can be done: Your Adsense in Someone's Inbox Hope it helps...