This doesn't really answer your question specifically, but one helpful way to think about it is to invert your process. Most people create content and then try to find a traffic source for it. The most successful marketers I know find traffic sources and then create content for them.
It's a lot harder than most people think. A fun exercise is to seek out some message board or facebook page for a group of people you have nothing in common with and see if you can repurpose or create content that engages them. Create a mailing list and see how many people you can get to sign up. It's great practice and you'll quickly realize how insanely difficult it is to interact with people regarding a subject they are passionate about without sounding like a paid shill. It's easy for those of us with a technical background to belittle the marketing folks, but there's an art to it that isn't readily apparent until you are staring at that proverbial empty piece of paper.
Edit: the oatmeal comics are a perfect example of this. The best advertising doesn't look like advertising.
Nah I totally get what you're saying. I'm just trying to teach myself some marketing skills at the moment (coming from a tech background) and I can't seem to get any traction at all. Interestingly I'm actually doing the exact mailing list thing you suggest already (conversionnewsletter.com). It's far harder than I though it would be from the outside and, as you say, great practice.
