Competitors can help you in many ways without knowing:
Link Building: “steal” their backlinks with the help of your own content of higher quality (Skyscraper Technique; there are many more link building strategies you can acknowledge in the WebCEO Help Center);
Promotion: develop your own marketing strategy on the basis of competitor data. Using your rivals’ promotional strategies and exploring their dark spots and underdeveloped aspects, you will be able to devise your strategy, avoiding pitfalls and applying approaches your competitors successfully implemented. In its turn, a wisely designed SEO marketing strategy will bring you top rankings and high profits.
Upgrading: see what new features and updates your competitors offer and then do them one better. This is one of the ways to analyze what the audience needs and how it welcomes improvements.
Inspiration: any enhancements in a competitor’s product will push you towards improvements in your own product.