forums are full of fraudy methods. In my first step, I have suspects if the end-user will really discover my project or it will be a site owner...
Google seems to do quite a good job of blocking click-fraud. I've only ever had a few campaigns that I couldn't make profitable, and they were due to the product range, pricing or simply low-price, low-margin products (where a conversion is not worth a lot, and as a result, you can't pay much for a click).