One of our shared company values is "We Default to Transparency," and we live this by exposing our company credit card spend to our Crew.
Transparency in company spend is a powerful way to align our Crew around how we spend our joint funds
A big thank-you to Brex for building this feature for us! This is something I used very successfully at my last startup (we had to build it ourselves), and the spend visibility is greatly appreciated by the Crew. It's also a really important way to create an MVP of company-wide fiscal responsibility because naturally, when you know everyone in the Crew can see how you're spending the company's money, you ensure that you spend it responsibly.
How our Spend Bot Works
Each time someone in our Crew uses our corporate credit card, an alert posts to a shared Slack channel called "spend-transparency", like this:

We've set the "money bag" emoji 💰 to equal $100, and we round up. So for example, the $135 transaction above showed two 💰. This is a quick and easy way to gauge how much money is being spent in the transaction.
We've also set a "high alert" threshold for transactions over $500, with an alarm emoji 🚨. Those transactions look like this:

We also have transactions that are higher than the alert threshold post to a second Slack channel called "high-spend-transparency."
If you're an early-stage startup and want to ensure your employees are "all in it together" with you around credit card spend, this is a great way to do it.