Shodan.io is the alternative. Kind of the biggest player in this field.

Quoting the web page: "Enterprises use Censys to understand their network attack surfaces. CERTs and security researchers use it to discover new threats and assess their global impact."

The details depend on how much the of advertised scan data enrichment they do, but you might for example ask how many vulnerable cable modems of a certain model there are in the network you are responsible for, and what ISP networks they are on.

You can likely take every public IP your organization has, run it through that, and see what your attack surface looks like. Very useful if you have an unmanageable and public computer network.

Isn't that something nmap does for free?

Not for wan which is where most commercial firewalls will do their magic.

To do this on wan you need to run zmap which is considered mean.

Huh. nmap cares not about wan vs lan.

You're correct, but i think it's that zmap scans way, way faster than nmap

Running software against my own IP space is considered mean?

There's no problem running nmap on WAN

So is this product overvalued?

Censys? Probably not. It depends how much you value having the data provided in an easily digestible and searchable form that's hopefully updated often.

On the other hand, if you have a small subnet, say, less than a /24, you might as well just nmap it yourself, and then you're also guaranteed to have the latest possible scan.

Maybe it's hush money.