With all due respect, unsuccessful e-mail campaigns are sent to the wrong people and/or don't say the right thing to them. As with any marketing effort, you need to approach people who, in the first place, could/should be interested in what you're selling. Then, you need to come up with the wording that will encourage them to give you an order.
If something doesn't work, the fault lies in the design of it, not the thing itself.
Duncan
