In which zone should I make a domain for the Internet service?

Question

Computer networks

I'll try to be brief and clear.
There is cloud software in b2b format. Type of online accounting. It is called "Soft" and is located at "soft.ru" (conditional addresses). This software includes a mobile application, but it is intended for the client's clients. Type users make an appointment with our client. The name of the application is the same - "Soft". Amendment: application users can see and can sign up with any of our clients. Now we have made a website that duplicates the functions of the "Soft" application.
Task: How to name this site and on what domain to place it? My version: the name "Soft", domain soft.COM.

Answer 1

- Soft App - application
- Soft.ru - site duplicating the application
- corp.soft.ru - site of the company itself
- sale.soft.ru - software sales site
, etc.