Summarize this article in one sentence.
The more late payments you make, the more likely the credit card company is to increase your APR. If you miss a payment, pay it as soon as possible. The company might report you to credit reporting agencies even before 30 days pass. This damages your credit rating in a way that takes a long time to undo. Keep your FICO score up by proving yourself to be a reliable debtor. The law requires your credit card company to give you 45 days' notice before raising your interest rate. However, the company might not give you an explanation for the rate change. If you don't get an explanation, call your credit card company to find out why your rate was changed. If the company can't give you a good answer, it might be time to transfer your balance to another credit card. Good reasons to raise your rate include consistently missed payments or a low credit score. Credit card companies are in the business of making money. They won’t lower your APR just because you're a good customer. If you want to be rewarded for your years of timely payments, you need to call your credit card company and convince it to change your rate.  Before calling your credit card company, research what a fair APR for your FICO score would be.  Then call your credit company and try to renegotiate your APR based on your research. If the company is unwilling to do so, it may make sense to transfer your balance to another credit card.

Summary:
Make your payments on time. Pay attention to rate increases. Try to lower your APR.