You might be curious as to how calculating your CPC is important. If you have a CPC that is too high, it is hard to have a good return on investment, or ROI, for your ad or business. It's easy for advertising costs to add up, and if you don't keep track of your marketing metrics like CPC, you could find yourself in a tough spot. Your return on investment, whether you're cost per each action is high or low, will tell you how much you are paying for clicks, and by what kind of quality you are getting for that investment.
For example, if you are an ecommerce store, and you only receive a small amount of clicks on your ad and your CPC is rather high, you most likely will lose more money in advertising the product than you'll make on actually selling said product. This can quickly cause a negative ROI for your business, and if you have a negative ROI, your marketing campaign isn't as successful as it could be.