[nickjj]

I think a big difference is Shopify's core product has a bunch of really useful things to help sell things. You don't need plugins or third party apps written by other developers to get a superb selling experience (note: I don't work at Shopify but I used the platform a few years ago and even wrote some custom apps / templates for it).

The benefit is the core product is insanely battle hardened and you can depend on it having a high degree of reliability (both from an up-time and code quality level).

Where as with WP, are you really going to cobble together a bunch of plugins written by anyone and then hope everything works? Maybe, but you'll also have to host it yourself too and now suddenly you're on the hook for site reliability -- unless you use a closed source WP hosting platform and now you're in the same boat as Shopify except it's worse because you have no idea what you're getting when it comes to reliability.

I think Shopify is a good example of how a niched down product can be successful. If you want to sell things, you want a platform designed to sell things. Not a generic CMS where you need to assemble a custom solution. This is especially true if you're not technical.

[unixhero]

You didn't mention Magneto, Prestashop ir WooCommerce in your comment.

[collinmanderson]

Shopify's core product is much better than Magneto and WooCommerce. (I don't have experience with Prestashop.)

Example: Shopify sends abandoned cart emails by default. With Magento you can't even see what items are in carts in the core product.

[thirdsun]

I used all of them and it’s really no comparison. Shopify is leagues ahead of them - for non-tech-savvy users and developers alike in my opinion.