When you sign up for a plan with Shopify, you can actually earn a commission for showing continuing development in your store and referring it to other merchants.
The commission is 20% of your chosen plan’s monthly price (the Shopify Starter plan is exempt).
So if you were on the Shopify Basic Plan for $29/month, you could earn a monthly $5.80 commission from Shopify as an official partner. Find out more about the program here.