Proliferation

The main reason credit cards are so major to debt recovery agencies is that they are so common. It is almost unheard of for a person over the age of 18 in the United States to not have a credit card of some kind.

Ease of use

Because they are small, plastic, and bear no resemblance to “real” money, credit cards are easier to use, especially for people who often have trouble spending large amounts of cash. Additionally, the lack of resemblance to “real” money often has holders thinking that credit cards aren't “real money”, which leads to them charging them more

Misinformation.

Many American citizens don't know the full workings of the credit card, let alone the impact it will have on their current and future debt. It is not uncommon for people to assume that because they pay on time, their credit is good. However, the magnitude of the debt—that is, how large it is in comparison to your income—is every bit as important as your payment history. Also, paying only minimum payments reflects badly on a person's credit report, as well as not paying off principal as quickly as needed. Some credit cards require only that the interest be paid off each month, leaving the principal untouched. This means that the full balance of principal is there, to be added to the next month—not to mention to be charged interest on later. This makes it all to easy for many people to build up high levels to debt without realizing it. Lastly, many people fail to realize that their credit card debt will begin to affect their other debts and finances. Your level of debt—that is, what percentage of your credit you are using—is roughly 30% of your credit score. Thus, a high credit debt will cause serious damage to your credit score, nearly as much as a bad payment history. This means that future interest rates will be higher, and that refinancing and reconsolidation are much harder—people are much less likely to finance such things for someone with poor credit than good. Because of these factors, credit card debt is the primary reason for debt collection agencies to be called in.