One of the great things about the internet is the transparency it brings. Pretty much anything your competitors are doing online to interact with customers, from marketing to social media, and even when and where they advertise can be easily discovered, and exploited to grow your business.
The simple reality is that your competitors are most likely spying on you, so why aren't you spying on them? From the technology that powers their website, to the advertising strategies they employ, you can see it all. You can learn from their mistakes, and build on their successes.
Happy Hunting.