Identify your competitors
You may know some of your competitors, but remember; you are working online. There are most likely lots! And they come and go all the time.
Often a company in an adjacent area will change its positioning to try and address your market, or a new startup may emerge in a related area. You need to create a master list of your key competitors and make sure you keep this up to date.
To do this, Google the terms which describe your industry, your products and services. You can also use a little known feature in Google. In the search box, type in "related:www.yourcompanyname.com" and Google will display a list of companies that it considers related to yours. Look for new companies that show up and see if any of these pose a threat.