I've made about $900 USD from mentioning Shopify in some of my blog posts, and it's definitely a solid affiliate program.

You get 2 months worth of someone's subscription if they signup, so $58USD from one person if they go for the basic plan. Since Shopify offers free trials they do a great job at downstream conversion and getting people to signup.

I think the real money is either in Shopify Plus referrals (you get $2,000 according to https://help.shopify.com/en/partners/how-to-earn#affiliate-referrals) or in becoming a Shopify Partner.

Shopify Partners get a recurring 10-20% of someone's membership fee. I don't know what the difference is in becoming an affiliate versus a partner, but now that I'm reading their terms again I want to find out lol.

But yeah, TLDR: I make $50 a month ish just by peppering Shopify links in some old blog posts. Definitely one of the higher converting affiliate programs in my opinion.

EDIT: here are the stats if you're curious https://imgur.com/nHDnGA8