Currently working on setting up a high-quality content providing company. The business plan is just about complete but this is really just a work of love and the result of my general hate of content farms (yes I have a day job).
Other than that I've been slowly putting together a site about bad dates for a friend of mine, maybe someone here will enjoy it enough to add a story ;)
http://www.runawayscreaming.com
Unless you could find a solid impression based advertising provider or are willing to spend the time finding advertisers I wouldn't add anything to the image itself except (maybe) the URL to your homepage. For the email bit you'd still have to be careful with the TOS that most pay-per-click ad agencies have regarding email.
Just thought I'd mention that personally I wouldn't mind an ad being placed in the return mail. Though I'm sure the privacy advocates would be against it, using OCR to determine keywords and targeting the ads would be beneficial for you as well as the consumer.
Other than that I've been slowly putting together a site about bad dates for a friend of mine, maybe someone here will enjoy it enough to add a story ;) http://www.runawayscreaming.com