Maybe you have already read about the licensing requirements for Dynamics 365 for Marketing. To keep it short: When licensing the marketing app for production there is no free possibility to get the app imported in a sandbox as well. You need an additional license for each sandbox you want to have the app installed.
You can install the marketing solution in a sandbox only when there is a license available in your tenant and not already configured for a Dynamics 365 organization. The reason is that there are not only data structures installed but also several Azure services required to provide the whole functionality.
Why would I need the marketing app in a sandbox?
Just some small examples:
As a solution architect, I want to have an infrastructure where all changes are only done in DEV and deployed to organizations like QA and PROD. I definitely want to avoid a scenario where certain metadata are only available in PROD.
After discussing this topic with Microsoft during several conversations they recommend the following approach:
1. Install Marketing App in PROD2. Backup/restore of PROD organization QA and DEV
Why I don't like this approach:
Therefore we will go with the following approach:
I hope Microsoft provides us in the near future a managed solution containing at least all necessary metadata to be installed in sandbox environments without the need for an additional license.
Update February 4th:
After some additional discussions and studying the docs again we found that there is an "uninstall" approach which probably better fits our needs. Therefore we go with the following approach:
According to this approach, only one Marketing license should be necessary to get the app metadata deployed in a proper manner in all organizations. The only drawback would be that the app in all organizations than PROD will be non-functional and maybe crash or hang or behave in a non-deterministic way.