It could be anything from a stock, to a counterfeit product that you thought was legit, a loan, a service that you paid for, etc.
For my freshman year in college I downloaded the free game "Injustice Gods Among Us" for my iPhone. I was sooo hooked that I literally spent some of my tax refund deposit to buy VC so I can buy/upgrade better characters. I spent a total of $349.96 on a free app in ONE go. I stopped playing the game before the semester ended...lol worst purchase.