I made the mistake of using a non-gmail account to check out Earth.
I found that Google take your details before proceeding to the financial demands – and when I got to that demands page I pulled the plug.

The SPAM still comes – and there is no way to stop it.

Does anybody know how to stop GoogleSPAM without setting up spam filters?

Seems like their ethics are rather questionable.

What financial demands? What spam?

Geagle Earth beta is free, always had been.

Maybe what you're referring to are spammers who are advertising Google Earth as bait for a subscription service they offer, which has NO CONNECTION to Google. It's simply a scam piggybacking onto Google Earth.

Be also aware that some criminals are advertising Google Earth downloads that are really malware that infects your computer and turns it into a spam zombie. The only place to get Google Earth is http://earth.google.com