I've been messing around with a few articles that do specific reviews of iPhone apps, but there seems to be almost no conversion on them. I don't want to waste more time writing the content if there really is no market. What I can't figure out is, every friend of mine with an iPhone has a dozen or more paid apps on their phone, most of them are in the 99c-1.99 range, and they have no problem paying that much. Clearly people are paying for them, but where are they learning about new / cool / fun / helpful ones? If you are making money at this, I'm curious to know how.
Keep your market in mind. A good portion of the market buying iPhone apps are teenagers. Teenagers, by and large, won't be looking up articles on the 'net about how to use their iPhones (at least for simple things like games). On the other hand, social marketing would probably work very well for that demographic .
Lots of competition right now in the "App Review" web vertical right now, with not much traffic to be honest. If you're going to try to make money off of iPhone related content, whether it be apps on the App Store, or a website talking about iPhone stuff, then you need to be creative and unique. Do something different. It sounds to me like right now you're doing what everyone else is, and that will get you nowhere fast.
Here's an article on iPhone app marketing... http://knol.google.com/k/william-broadbent/iphone-app-marketing Find a few journalists you like and send them some emails and a few letters. One good article is all you need.