I've also had friends who have had their MailChimp accounts deleted or locked without explanation, warning, or recourse, so I wouldn't rely on MC specifically f

I've also had friends who have had their MailChimp accounts deleted or locked without explanation, warning, or recourse, so I wouldn't rely on MC specifically for anything business-critical. That said, if you have business-critical data on any cloud provider, you should be exporting periodic backups of that data to another provider so you don't lose access to it all if a single provider shuts down your account.