the ads you are using are really helping you or not at all...if not you may want to analyze the ads you are using and how to improve them
Here I'm posting what I think is the most important things to watch...
*Average daily cost
*How much did I spend last month?
*Is my site reachable on the web?
*Traffic on my site, is it worth it?
*If using ads are they useful? is people actually clicking my ads?
*The percentage of people entering & buying