I personally would suggest to start a business creating WooCommerce websites. At least you'll be owning the whole profit and would not depend from the whishes and decisions of a wannabe BigCorp. As an additional plus you help spreading open source software.
Shopify Merchants are selling roughly $80B a year, at least 5x WooCommerce merchants. Paying Shopify 20% means you net at least three times higher monthly revenues over paying WooCommerce zero commission.
Apple charges devs 30%, but in return you get access to the worlds highest volume App Store paying developers $35B a year. You can also make iOS apps using an enterprise certificate, and distribute to tens of thousands with zero commission, but no one will ever find you on the store search, or give you public App Store ratings, you’ll never appear in a top category list or get featured by Apple, and any potential customers you reach will be leery of using your custom payments or subscription system, leading to lower paid conversions.
This seems a weird way to calculate potential eCommerce platform plugin profits because (unless you are a payment gateway), the quantity of stores is more important than the volume those stores sell, and WooCommerce is by far the most popular eCommerce platform.
For example, Kylie Jenner's Shopify store has approx. $330mm[1] in revenue a year as far as I can tell, but that's only going to translate into one potential plugin purchase.
[1] https://www.theedgemarkets.com/article/tech-how-shopify-turn...
Kylies a bad example, since her dev team can presumably afford to build the specific custom features they need.
Merchants in the $100K to a few million a month range aren’t likely to be able to afford much custom development, but won’t blink an eye at paying hundreds of dollars a month for useful apps. A $10k a month merchant might balk at spending a $100 a month on anything but mission critical apps, and a $1K a month merchant probably isn’t buying any apps.
But when Shopify sales volumes are at least 5x Woo Commerce (more likely over 10x because I don’t believe Woos numbers), odds are Shopify is much bigger in every customer segment.
The benefit of App Stores is getting a access to a mass number of qualified customers anxious to add compelling features to the platform they bought, be it a web store front or iPhone. The negative is the platform has to always keep moving ahead, and sometimes your app is right in its path.
We used to call it picking up nickles in front of the SteamRoller back in my Photoshop Plug-ins days. Was very frustrating, but still very lucrative. I have often talked about giving a demo of my next brilliant plugin to the Photoshop team lead and product manager just before the release of Photoshop 3. Three weeks later Photoshop3 was released with their version of my plugin in it.
Can't have multiple discounts in the cart? Splution: create custom discount codes on the fly for absolutely everyone in real-time.
Stealing the good ideas and adding them to the core platform would generate more money short term but would destroy the app store
Otherwise it’s possible for someone to integrate your stuff into their store even outside of the Shopify store (by integrating JS snippets for example).