It is not on any "KeyServer"
$ gpg --search "73D9A8A4"
gpg: zoeken naar '73D9A8A4' van de hkps server hkps.pool.sks-keyservers.net
(1) Andy Canfield
2048 bit RSA key 73D9A8A4, aangemaakt: 2014-08-03
However, it's not associated with your email address, so no mail client can understand it to use it.
Later, you say:
and the public key you get from my web site should confirm the signature.
But I can't trust your site, because it's not HTTPS (which isn't perfect, but is better.) You can get free SSL certs. And I can't trust your key because it's not in the web of trust.
Basically, you have a PGP key, but it's useless for many cases because you haven't done some simple steps to make it useable. I could never trust any signed message to actually be for you, and I can't trust the information I have to encrypt something to you.
Also, yes keyservers can be subverted by the NSA etc. They can also be subverted by me. They're insecure by design, and so that makes them safer.