Definition: A call to action (CTA) is the part of a post or ad that tells people the one specific thing to do next, such as comment, save, visit a link, sign up or buy.
Also called: CTA, CTA button
Updated October 11, 2026
A CTA can sit in the caption, on the image or video, in the first comment, or on a button. Match it to the goal of the post and to what the platform makes easy.
Paid posts usually carry a button instead of, or as well as, a caption CTA. Meta’s Business Help Centre lists which call-to-action buttons are available for each campaign objective in Ads Manager, and Facebook Pages have their own action button for things like messaging or booking. Pick the button that matches the landing page: “Learn more” for an article, “Sign up” for a form, “Shop now” for a product.
Ask for one thing per post. Start with a verb, say what people get (“Get the 10-step checklist”, not “Click here”), and make the step small enough to do from a phone in a few seconds. Put the CTA where people will see it: at the end of a short caption, on the last carousel slide, or spoken and shown on screen in a video. Then measure the action you asked for (comments, saves or clicks) rather than likes.
Each network rewards different actions, so the same post often needs a different CTA per platform. In Postprism you write one post and tailor the version for each network, so the LinkedIn version can ask for a comment while the Pinterest version asks for a save.
A fitness coach posts a 6-slide carousel of desk stretches. The last slide says “Save this and do it at 3 pm tomorrow”. Saves on the post are four times her usual rate, because the post asked for exactly that.
A hook is the opening of a post (the first line of text, the first slide or the first seconds of a video) designed to make people stop scrolling and keep reading or watching.
Click-through rate is the percentage of people who clicked a link in a post out of everyone who saw it.
Conversion rate is the percentage of people who completed a goal, such as a purchase, sign-up or download, out of everyone who clicked or visited from a given source.
“Link in bio” is a phrase used in a post to send people to the clickable link on the account’s profile, used on apps such as Instagram and TikTok where the profile is the main place a link can go.
The first comment is a comment the author posts on their own post straight after publishing, usually to hold a link, extra hashtags or a call to action.
Write once, tailor each version yourself or with optional AI, and schedule to 6 networks from one calendar.