The model which is used to find the average credit score is to the advantage of the consumer rather than the commonly used middle score one. In many cases in the USA the average credit score is mainly used by sub-prime lenders. These sub-prime lenders lend money to people who have a credit rating other than an A or A-. With the middle credit score model your lender looks at the 3 scores in your report and looks directly in the middle. For example if you have scores of 720, 676, and 660 the lender takes the 676 number and then your loan conditions are based on the 676 number.
The national average in the USA seems to be anywhere in the 580-650 range for credit scores. Even with the national average you can generally still qualify for loans or credit cards with an average score. Some things that can taint an average score though is missing payments and definitely a past bankruptcy. Having an average credit score by no means you will not qualify for loans or credit cards.
The rating you have can be changed over time, for bad or worse, it all depends on how you pay your bills. Obviously you will get better interest rates on loans and credit cards if you have an above average credit rating. If you are on the lower side of the average credit score than you need to be careful not to dip down too much or it could seriously hurt your credit and defiantly the chance for lower interest rates. Keep on top of your credit rating and make sure to check it at least one time a year so you know where you stand in terms of your credit.
Having an average credit score is by no means a bad thing as you can still qualify for many things but there is always room for improvement as with a better credit score comes more financial advantages.