I'm Jason a Guru here at Shopify.
It would be possible to open two different stores, one under www.example.com (for example), and the other at its subdomain, example.mystore.com.
Also, to make sure that this is clear, you'll need to operate these separately on two separate Shopify accounts!
In terms of how to set this up, it does depend slightly on whether or not you purchase the domain from Shopify. If you purchase the domain for store #1, you'll then add this subdomain as an existing domain in store #2, both cases within Online Store > Domains.
Although currently, it is not possible to run multiple stores under one account/admin, it is possible as I mentioned to have two different stores under one Domain, having the second as a Sub-Domain!
You can add multiple Domains to one store and have them all redirect to the same place - but if it's going to be a different online storefront, with different suppliers/warehouses/products/etc, then you'd need an entirely separate account.
I hope this helps, let us know if there is anything else we can help you out with! - Jason
Just saw your reply and noticed a mistake: You wrote "It would be possible to open two different stores, one under www.example.com (for example), and the other at its subdomain, example.mystore.com."
A subdomain always appears BEFORE the main domain, e.g. mystore.example.com and not example.mystore.com as in your example, which would be correct if mystore.com is the main domain, and example is a subdomain.
As it relates to the question posed in this thread, is there a limit to the number of subdomains that a store can have? And can each subdomain have its on login? And does each sub domain have a seperate monthly fee? Lastly, is there information on this that you can point us to so that we may learn more.
Ok, I have no problem with paying for two stores.
What I do have a problem with I bought 2 new domains of you guys in my prior store to make two new stores not to connect to my prior one. Can I move them to another store account when I open that account??
Or am I sitting on a goldmine in one store :D
Ash here from the Shopify team.
You can absolutely transfer a domain purchased through Shopify from one Shopify account to another. We have a great document here which goes through the steps to make this happen! When you finish going through the steps for the transfer, it will take up to 24 hours for the transfer to complete. Once completed, email forwarding and DNS records will transfer along with the domain.
Let us know if you have any issues with transferring your domain between stores, and our team will be happy to assist.