You go to the agent, who says the phone company has a promotion: send $50 to someone and receive $15 in top-up airtime credit! Your roommate says if you send $50 to her, she'll send it right back, plus $10 for you to send her the bonus airtime.
What should you do?
After the agent fees, you'll make a few dollars in exchange for airtime that you don’t need. You like this plan! You deposit all your money.
You think it sounds risky. And confusing! You only want to try for now, $50 is far too much. You deposit $25, to keep things simple for now.