Short answer: because there's no request in it yet, on purpose. That opening line is step one of a well-documented gift card scam, not step two.
A text or message arrives from a number you don't recognize, or sometimes one that appears to belong to someone you know, often because their account or contacts were compromised elsewhere. It opens casually: "Hey, can you do me a favor?" or "Are you busy right now?" There's no request yet, that's deliberate, it's designed to get you replying and building a normal-feeling exchange before the real ask shows up.
Once you respond, the story shifts. The sender claims to be a friend, a boss, or a faith leader, and says they urgently need a gift card, for a birthday, a work event, or someone in need, promising to pay you back. Once you buy it, they ask for a photo of the card and its code.
The moment you send that photo, the money is gone. Gift cards cannot be reversed or traced once the code is shared, which is exactly why scammers ask for them specifically.
The two-step structure is what makes this effective. A message that opens with an immediate, urgent request for money reads as suspicious to most people. A message that opens with nothing more than "hey, are you free?" reads as completely normal, so by the time the actual ask arrives, you're already mid-conversation and less on guard.
If the message claims to be from someone you know, don't reply to it at all. Call or message that person directly using a number you already have saved, not the one the text came from. If it's truly a stranger, simply don't engage, there's no legitimate reason for someone you don't know to need a favor from you over text. And no matter who's asking, never buy a gift card for someone else's "emergency" and send them the code, that single action is what makes the scam succeed.
This is one trick out of dozens. The Scam-Proof Playbook covers phishing, phone scams, protecting your family, and more, in plain language, with real examples.