I hate spam. When I find a topic/site/area of interest on a website, I'll sign up on their opt-in newsletter emails. This is not spam, but something I'm asking for. Now, once I get a few of emails from a particular site that contains content relevant to what I want, and they happen to list a product/service - this is the one I'll buy. Why? Because now I trust them. But this doesn't mean that if you are marketing this way, and you have no conversions yet, but plenty of members, that your failing. Now, because you see, your email marketing offering will keep your members "engaged with you", even though they are not ready to buy at the present time. Just remember that your target audience won't buy when you're ready to sell, but they'll buy when they're ready to buy.