One of my main use cases for Google Vault is helping customers to export data from Gmail, whether they want to move the data from one Gmail account to another, or for other reasons. Another common use case is for searching for information within Gmail and other products in Google Workspace.
We often get users who are facing some kind of challenge like not having enough storage space to backup their Workspace data, and this situation might be better solved by using Google Vault. Thus, we come in and ask the customer if they would like us to upgrade their plan and enable Google Vault to help record and back up their data, and if they agree then we help them to get it working.
We are a reseller of Google products and we have 1000+ customers who use Google Workspace. Out of these customers, over 500 are now using Google Vault as well.