When it is time to pay your credit card bills, check your transaction history to verify that all transactions are authorised by you. Many times we give our credit card details to online merchants who may be charging us some (deceptively small) monthly fee without us even realising. I recently found out that I was being charged $20 a month for an online service for the past 4 months without even realising it. Luckily I decided to read my transaction history this time around and found it and put an end to it.
That is the problem with online transactions. And credit cards. You don’t feel the pinch of money going away because it not a physical act you perform. Just some mindless button clicks and voila, you can throw away your entire paycheck and not even realise it.