i don't need to provide my (potentially vulnerable) production URL to whoever-you-might-be in order to identify the last 6 months of vulnerabilities - I can just google for that.
Submitting your site to this is just asking for trouble.
Submitting your site to this is just asking for trouble.
My web logs are full of automated scanners. Once when I ran a vulnerable version of Wordpress it got discovered and pwned very quickly. No need to enter the URL in any website ;)
It's kind of clever marketing, giving people a sense that they're going to get a security audit in exchange for an email address.
I hope that if you subscribe, the site regularly rescans your stack and realised if it’s changed. Otherwise it’s just a mailing list subscription that becomes out of date and therefore not useful.