This rule was first introduced in the first book of Terry Goodkind's Sword of Truth series. In short that rule is:
People are stupid
And here is a prime example of someone applying this rule for the Christmas season.
Excerpts from a letter:
My dear x,
the night of Christmas Eve is going to be a very special night for you this year. In this very night a miracle might happen to you...
Yes, the night of Christmas Eve 2000 will be an important cornerstone in your life. In the night from 24th to 25th Dec. 2000 between 0:30 and 2:00 in the morning an extremely positive phenomenon, I should rather say a cosmic happening, will influence you directly.
Yes, X, in this mystical night, which stands in the sign of rebirth, love and hope, I would like to perform a magickal ritual for you, so that you will enjoy perfect luck in your life forever.
In regard of your birth horoscope we can see one important fact. The moon energies, which are important for your luck, will be in complete harmony with the other powers of the zodiac.
For that reason, it will be the ideal magickal time to perform this magickal rite so that luck will be with you every day of your life. Exactly that will happen, if you would want it...
The letter continues with the repeating "magickal rite", "personalised just for you", "magickal time", "perfect timing" etc. It's interesting to see how many people fall for that prime piece of shit. And this wonderful altruistic woman who has just her customers benefits in mind will get richer and richer.
All in all I must say it's a prime example on how to apply Wizards First Rule for successful money magick purposes. Yours of course, not those for whom you cast such spells. It only takes some time to set up one such letter. The names can always be exchanged later on. Getting some weird stuff together to send the customers after that "magickal rite" shouldn't be much of a problem. Considering how much she charges for that stuff, it's really quite lucrative.
The only critic I must add is that the letter itself promises too much, but apart from that it's quite good. Personalised address (if only she wouldn't have had her signature printed at the end), addressed to the first name, adding birth date and astrology and of course making the addresant feel important ("will influence you directly" and basically saying that she'll stay up in that special night just for the customer instead of celebrating with the family or whatever else she does at Xmas nights).
People will always buy into that stuff. I wonder what chaos mages would come up with if this sort of thing wouldn't be beneath their standards - speaking of course of those I know ;-)
Other than that, such letters, with different contents can be easily applied for other things as well, protection, curses, love, you name it. It just needs a tad belief of the recepient and it usually works.