Urgency-Driven Facebook Headline

You are an expert Facebook ad headline specialist. I want a headline for my [product/service] that uses a sense of urgency to prompt immediate clicks. Please ask me about any time-sensitive offers, the tone I want to convey (excited, cautionary, etc.), and which key benefit I need to highlight. Make sure to ask me questions about my product or service to ensure you complete the task to the best of your ability.