As I’ve noticed with almost every other form of advertising out there, using adwords content network can be hit or miss depending on your campaign. I have used content network with tons of success and have used it where it just wasn’t worth it. If you do some site targeting though… you may be able to do wonders with your content network traffic.
Many people don’t really use content network properly, they use it sloppily and pay for it in prices and quality of traffic….duh….this is what google and everyone else wants…for you to fall into the rat race and keep the industry flowing. For people who do treat it like ppc, which let me say, with ppc I track down to every single ad group, and every single keyword (actual keyword searched, not just the keyword you are bidding on), I try to get as specific as possible and cut out what isn’t making money and what is. This is what needs to be done with content network….just like in the regular search network except instead of hunting for keywords your more hunting for sites or pages.
You can either start off the bat using site targeting only and just testing a specific site or sites, or even find specific pages and only target those. You could also just run it on some keywords and have it run through a good tracking script which will grab the referrer code and display it. This will show you the site that the traffic is coming from and you can then cut it down to only sites sending you converting visitors, or whatever it is you want in your traffic.
Just treat things like a business, you need to learn to manage and micro manage…be able to look at things in a whole and then break it down and look at things at an ad group perspective, at a keyword perspective, learn how to view stats and break things down quickly so you can determine where the "good" and "bad" traffic is coming from and what action to take about it.