[greenshackle2]

You can provide the software as a service BUT you have to give the source code to all users, including your modifications if you have made any.

In other words - you can't sell SaaS based on AGPL software + proprietary secret sauce, you have to share back your secret sauce with all users.

It doesn't prevent you from selling it as SaaS, I could sell vanilla Mattermost as a service under AGPL, my selling point might be that I provide high reliability and excellent support.

Do you have an example of that dual license?

I don't see how that would work, the first person you give an MIT license to can re-distribute it under MIT to anyone else, including corporations.

Usually for dual-license you have the opposite, you would have a restrictive license like AGPL for the public, and you would sell non-free licenses with no redistribution rights that allow modifications without sharing back, for corporate clients who want to add their secret sauce to the software without having to give away the secret sauce for free.