Easy Money

In the days before ultrasound, an enterprising chap put out an advert:
Money back guarantee : Proven method tells you the gender of your unborn baby. Send $10, your date of birth, date of conception etc, to....

Thousands of suckers sent in their money. In each case the response came back: "It's a boy!"
He was right - in about 50% of the cases. The other half got their money back.
Ka-ching!

Apparently, this sort of scam is now illegal [Ed: proof that we don't have an adequate education system?]

Fine, perhaps we need protection from our own lazy thinking. But how is the above example any different to taking money for providing horoscope predictions?