This might not be exactly a tactic on how to get online traffic and promote a business but keyword research is still a preparatory act for any marketing campaign. Keywords are essentially the lines and phrases that people you are trying to target usually type in the search box to look for information that your business can provide.
Essentially, keyword research helps you understand the mind frame of your audience so you could adjust the way you present your content. With these keywords, you can create content that is bound to answer whatever query your audience has.
Of course, the search engines have their rules as regards the incorporation of keywords. It has to be natural and does not break the line of thought of your content. It also has to appear at the right amount in your pages as stuffing can cause a demotion in the SERPs.
There are several tools that you can use for research which include SEMrush, Ahrefs, and Moz. You can also hire an SEO agency to do this (and other SEO-related strategies) if you have the budget for their services.