There has been recent speculation by the financial press that 0% credit cards will soon be a thing of the past as they cost the credit card companies so much money. If so then the comparison of interest rates and in particular the APR will become more important once again. At the moment most cards have 0% offers and this is used as the attention grabbing marketing tool. However, you will always see the standard APR quoted as regulations insist that it is always present on advertising.
The standard APR (Annual Percentage Rate) is calculated from not only the interest rate of the card, but also includes charges and fees. It is an attempt to standardise interest rates across all credit cards and so make comparisons meaningful. The standard APRstandard apr calculation is really the only one to use tio find the lowest interest rates on credit cards (or other financial products for that matter).
If you are looking to obtain a 0% interest card or similiar then it is doubly important that you remain aware of the APR of the card as this is the rate that will kick in once the 0% offer expires. The credit card company is relying on the fact that many people simply don't bother to change cards regardless of the rate and simply see the monthly interest as a necessary evil.
The introduction of the APR has made the comparison of credit cards much easier as it has become very difficult for credit card companies to hard the nasty surprises such as charges in the small print.