One year ago I tried to make a shopify based e-shop, however after one month my shop failed. I understood that I need to have my own audience if I want to try again without using my own money for ads. So I created 5 different instagram accounts and gathered more than 30 k followers in total. So now I'm looking for a partner. I have some audience, you have a shop, so let's collaborate.
You might be able to turn this into a good business selling Instagram accounts to people in the niche if the engagement is good.
Or be an "influencer" and join the affiliate programs of stores in your niches.
Collaborations like this work well if you work with legit brands, and your audiences are legit.