In order to know if an advertising campaign is successful or not, whatever was invested is compared against total sales, resulting in ROI (Return on investment). If you invest in traditional advertising methods like TV or radio, it becomes very complicated to measure this. With Digital Marketing, all these data is generated automatically.
Everything is measurable in online advertising, this way we get so much data that some times is difficult to know which of all these data is actually relevant. One piece of data we recommend to calculate is your CPA, which tells your company how much does it cost to generate a customer. This can be done very easily, you just need to divide the investment cost between the number of customers obtained (CPA = Investment/Customers).
But, If your business is trying to improve its position with Search Engine Optimization (SEO), Google Adwords, Facebook Ads or Social Media, CPA can be calculated with each one of these separately so you can see which campaign is being more effective.