Dark web monitoring is sold heavily and explained badly. Here is a straight account.

What it does. Services scan breach dumps, criminal marketplaces and paste sites for your domain, and tell you when credentials associated with it turn up. That is genuinely useful information.

What it does not do. It does not scan the dark web in any complete sense, because no such index exists. It sees what has been collected. It cannot tell you whether a password is still in use, whether it was ever real, or whether anyone has tried it. And it cannot remove anything, because once data is out it is out.

The honest value

Most reports come back with hits, and this alarms people unnecessarily. Almost every business with staff who have ever used a work email address to sign up for anything will appear in some breach corpus. That is normal.

The signal worth acting on is narrower: a current employee, with a password that is still in use, particularly on an account without multi factor authentication.

What to do with an alert

Reset the password, if it is still current. Obvious, frequently not done.

Check whether that password was reused. This is the real risk. A password from a 2019 breach at a shopping site matters enormously if the same one protects your email today.

Verify multi factor authentication is on that account. With it, a leaked password is largely an inconvenience. Without it, it is an open door.

Look for signs it was already used. Unfamiliar logins, forwarding rules you did not create, sent messages you did not send. Mailbox rules are the classic finding and almost nobody checks.

Is it worth paying for

As a standalone product bought out of fear, probably not. As one signal among several, sitting alongside multi factor authentication and a password manager, yes.

If you have to choose between paying for monitoring and rolling out multi factor authentication across the business, do the second one. Monitoring tells you about a risk. Multi factor authentication removes most of it.