THINGS YOU MIGHT NOT KNOW ABOUT CREDIT CARDS

THERE ARE ENOUGH CREDIT CARDS IN CIRCULATION

TO WRAP AROUND THE EARTH AT THE EQUATOR

THREE AND A HALF TIMES

THE FIRST GENERAL CREDIT CARDS WERE MADE OUT

OF PAPER

THE REASON CREDIT CARDS EXPIRE IS BECAUSE

THE MAGNETIC STRIP SUFFERS A LOT OF ABUSE.

TYPICALLY IT WILL LAST AROUND THREE TO FOUR YEARS

THIS MEANS THAT YOU CAN TECHNICALLY STILL

USE YOUR CREDIT CARD AFTER IT EXPIRES AS LONG

AS YOU ARE NOT ASKED FOR THE EXPIRATION DATE

(EVER NOTICE THAT ALL THE OTHER DETAILS

STAY THE SAME?)

CREDIT CARDS FOLLOW THE LUHN ALGORITHM,

WHICH IS A CHECKSUM TEST ON A NUMBER.

IT CAN TELL YOU IF THE CARD IS VALID OR NOT

TO SEE IT IN ACTION, START ON THE RIGHT AND

DOUBLE EACH SECOND DIGIT (2121 WOULD BECOME 4141).

THEN ADD THEM TOGETHER AND YOU SHOULD END UP

WITH A NUMBER DIVISIBLE BY 10. IF NOT,

THE CARD IS NOT VALID.

THE AVERAGE AMERICAN HOUSEHOLD RECEIVES

6 CREDIT CARD OFFERS EVERY MONTH

IN 2006, CREDIT CARD COMPANIES EARNED MORE THAN

£63 BILLION IN INTEREST

VISA STANDS FOR VISA INTERNATIONAL SERVICE

ASSOCIATION. THIS IS KNOWN AS A RECURSIVE

ACRONYM BECAUSE IT REFERS TO ITSELF.