What is real profit or loss from running e-commerce store like Shopify?

I am looking to jump into running e-commerce store. All information found so far indicates many people have moved on from selling stuff to selling courses. So my question is, do you run an e-commerce store? How much time do you spend and what’s the profit or loss (mention range if you don’t want to say numbers).

I want to know what’s involved before jumping in. I also have a few questions if I can ask over email. Please point to your profile or other media (Twitter/website) if you are willing to share.