If you haven't mastered all the internet marketing metrics yet, you should know this; conversion does not always mean a sale. It is a specific action taken by the user, who adopts a different role after that action.
For instance, a user visits your website, at this moment they are only a reader. Now when they submit a form, trading their information for exclusive content, they convert and become a lead; their role and value change.
Numbers like reach, bounce rate, time on website are merely hints that give you an idea about the current situation. All those metrics should serve to the sole purpose of increasing your conversion rate.
And although you will come across the term Conversion Rate Optimization (CRO) a lot when reading about e-commerce marketing, so much that you would think it's specifically an e-commerce tactic, in reality, conversion is vital for ALL businesses who want to generate online ROI.