Marketing that asks for a specific, measurable action right now. The opposite of 'brand awareness.'
Direct response is any marketing where you can tell, in real time, whether it worked. Someone sees your ad, reads your email, lands on your page, and either does the thing you asked for (buy, sign up, book a call) or they don't. The response is direct, measurable, and immediate. That makes it the opposite of 'brand marketing,' which works over years through vague effects.
If you can't afford to wait years to see if marketing worked, you need direct response. It's how small businesses survive. Every dollar in, track every dollar out. The entire discipline of direct response is about making marketing accountable.