Facebook Messenger ads are a type of social media advertising that allows businesses to engage in personalized conversations with customers on messaging channels like Facebook and WhatsApp. These ads can be placed across Meta's properties, including Facebook, Instagram, WhatsApp, and Instagram, and can lead to better conversions by inviting users to start a conversation. The benefits of Facebook Messenger ads include reaching qualified leads, starting a conversation, leveraging chatbots, and achieving higher ROI through personalization. By using platforms like Twilio's Conversations API, businesses can seamlessly integrate conversational ads with their existing channels and scale to new ones.