Anne-Marie’s business goal is to generate online sales of her handmade purses. Her AdWords costs are $100 per week and she wants to know if her advertising investment is paying off. What additional information do you need in order to calculate her return on investment (ROI)
Number of clicks on her ads and costs to produce her purses
How many times her ads have been viewed and clicked on
Number of clicks on her ads and revenue they generated
Costs to produce her purses and revenue generated from her ads
ROI is the ratio of your net profit to your costs. It’s typically the most important measurement for an advertiser because it’s based on your specific advertising goals and shows the real effect your advertising efforts have on your business. The exact method you use to calculate ROI depends upon the goals of your campaign.
Read more here: https://support.google.com/adwords/answer/1722066?hl=en