Credit Cards can put you into debt first and foremost if you are not aware of how they work, and if you are not mindful of how you use them .
Credit cards are good if you use them right. Not paying any bill will add negative history to your credit profile. The same applies for Credit Cards. You never want to pay them late, late marks on credit cards make lenders view you as unreliable for paying back their money you borrowed.
Credit Cards work best for your scores if their limits are high.
Higher limit cards are very useful if you plan to make large purchases or are trying to build capital by showing higher credit limits. However smaller limit department store cards also look good on your credit profile.
Credit Card Gimmicks are Bad
Credit Card gimmicks are companies that ask you to pay a small fee to obtain an account with the company. Some companies like Capital One ask you to pay a small fee to open some of their bad credit lending cards. Other companies such as My Jewelers Club ask you to pay in a membership fee and make a minimum purchase, then give you a 5k limit guaranteed. So Not all gimmicks are bad. So just make sure you do your research, always.