Know-How Exchange : E-Marketing

So who is your target audience and what do you want them to do when they learn about your product?

I don't quite get it. The call-to-action is very specifically the thing you want your target audience to do. So what is that?

Also, please be clear about who the target audience is. Is it medical professionals, consumers, insurance companies, etc? Where? What country/continent? What specialty or sub-specialty?

The most effective call to action relates to what you want the person reading the message to do. Do you want them to buy, to read more info, etc. - your call should relate to that.

Entering a contest as the call to action may get your more entries, but not necessarily quality ones. This is really only useful if the end goal is to gather leads which you will follow up with later. But be aware that there will be people who aren't qualified who only took the action of entering for the prize.

Convert it to research: why end users like most and least in your sroduct segment, what are the brightest experiences using and miracle healings, what these professionals would do or appreciate as most appreciated improvement.
Promise a third party charity donation: "each reply received we will give X$ for XXX charity fund..."
Conceal your procuct message on research form landing page and emailer.