> ## Documentation Index > Fetch the complete documentation index at: https://docs-next.gallabox.com/llms.txt > Use this file to discover all available pages before exploring further. # Ad Engagement Window > The extended free messaging window Meta grants when a customer messages you from a Click-to-WhatsApp ad or a Facebook/Instagram Page button — up to 72 hours, and why it doesn't reset like a normal conversation. When a customer starts a conversation by tapping a **Click-to-WhatsApp ad** or a **Facebook/Instagram Page button**, Meta grants a longer free messaging window than the standard 24-hour service window — Gallabox calls this the **Ad Engagement Window**. ## How it's different from the standard window The [standard 24-hour service window](/pricing-and-billing/message-credits) **rolls forward** — every new message from the customer resets the clock to another 24 hours. The Ad Engagement Window works differently: * It's granted once, when the customer first messages you from the ad or Page button. * It runs for **up to 72 hours** in total (an initial 24-hour window, extended by an additional 48 hours that Meta grants specifically for these ad-originated conversations). * It's **static, not rolling** — it does not extend further no matter how many times the customer replies within it. Once the 72 hours are up, it's over, even mid-conversation. Gallabox reflects the window status that Meta reports for the conversation — the countdown you see follows Meta's own timing rather than being recalculated locally. ## What's free during the window Any message you send — free-form text or any template category — is free for the duration of the Ad Engagement Window. ## After it expires Once the Ad Engagement Window closes, standard pricing rules apply again: you're back to the regular 24-hour service window and [category-based template pricing](/pricing-and-billing/message-credits). ## Related Articles * [Message Credits](/pricing-and-billing/message-credits) — the standard window, template categories, and the wallet these charges are deducted from * [Reduce Your WhatsApp Message Costs](/guide/reduce-whatsapp-message-costs) — using this window to start conversations at no cost