Just wanted to extend a thanks to the STM members here who have been putting up such good quality content and comments. I managed to throw together a campaign (email submit, AdWords traffic, landing page) and turn a profit all in about 24 hours, which is good motivation to build out.
Obviously it's not always as easy, especially if you want to get beyond the $3 profit margin, but if it's in the black, it's in the black. 
Will try and learn a bit more and then happily write up the experience if anyone's interested (although I'm pretty green at this whole thing).
Mods: Sorry, this would be better in the Newbie area
Congratulations! Make sure you don't get upset if you see your campaign go into the red. These things fluctuate on a day-to-day basis until you get an idea of what's working and the campaign becomes stable. Even if it continues to make a profit, there's no reason you should skip testing - test new targets in AdWords, new landing pages, split test headlines and body text on the landing pages, graphics on the landing pages, adcopy in AdWords, etc. With a few small tweaks you could turn a small profit into a decent one, but you'll never know if you get complacent and let things ride.
Keep up the good work though, and congrats on making money with AdWords - I know a lot of people have given up on them due to Google being a bunch of jerks when it comes to approving anything.
It's awesome to see those first few dollars - it just gives you a glimpse of what is possible.
Put in the hard work and the rewards will come - that's the best part about this industry.
Nice work!
congratz man! always good to see success stories 
Nice work Billy! I moved the message for you as well
Congratulations mate! Keep it up and you'll reach all your goals!