# How Meta ads work: formats, placements and the auction _One campaign, four formats, placements across five apps._ > A practical guide to Meta ads in 2026, covering the four ad formats and their specs, where ads run, how the auction picks a winner and how to measure results. - Tags: Guides, Growth - Published: 2026-09-29 - Category: Guides - Author: insidethebox - Topics: AI, Product - Reading time: 7 min - Source: https://www.insidethebox.dev/insights/how-meta-ads-work Meta ads run across Facebook, Instagram, Messenger, Threads, WhatsApp and thousands of partner apps. This guide covers what you choose as an advertiser: the format, where it runs, how Meta decides who sees it, and how you measure what it earns. ## What are Meta ads? Meta ads are paid placements across Meta's apps. Meta says its apps reach 3.6 billion people every day (June 2026). You build a campaign once in Ads Manager, and Meta's delivery system decides which person sees which ad, in which placement, at what price. Every campaign starts with one of six objectives: Awareness, Traffic, Engagement, Leads, App promotion or Sales. The objective tells delivery what to look for, whether that is people likely to remember the ad or people likely to buy. ## Ad formats and specs Meta offers four core formats, and each one adapts to the placements it runs in. - **Image:** a single photo with an optional footer. Best for one clear message. - **Video:** from short vertical clips for Reels and Stories to longer videos in feeds. Best for showing a product in use. - **Carousel:** 2 to 10 images or videos in one ad, each card with its own headline, link and button. Best for several products or the steps of a story. - **Collection:** a cover image or video above three products from your catalog. Tapping the cover opens a full-screen Instant Experience, and tapping a product opens its page. | Format | Facebook Feed | Stories and Reels | Text on Facebook Feed | | --- | --- | --- | --- | | Image | 4:5, 1440 × 1800 px, JPG or PNG up to 30 MB | 9:16, 1440 × 2560 px | Primary 50–150 characters, headline 27 | | Video | 4:5, 1440 × 1800 px, MP4 or MOV | 9:16, 1440 × 2560 px | Primary 50–150 characters, headline 27 | | Carousel | 2 to 10 cards at 1:1, 1080 px or larger | 9:16 cards | Primary 80, headline 20, description 18 | | Collection | Cover plus 3 products | Cover plus 2 products on Instagram Stories | Primary 125, headline 40 | Two details trip people up. In Stories and Reels, keep about 14% at the top, 35% at the bottom and 6% at each side free of text and logos, because the app's own controls sit there. And Reels allow far less text than feeds: an Instagram Reels caption should stay within 44 characters. ## Placements and Advantage+ placements Placements are where ads appear. Ads Manager groups them into five sets: - **Feeds:** Facebook Feed, Marketplace and the right column on desktop, Instagram Feed and profile feeds, Instagram Explore and the Threads feed. - **Stories, Status and Reels:** Facebook and Instagram Stories and Reels, Messenger Stories and WhatsApp Status. - **In-stream ads for reels:** ads before, during or after Facebook reels, and banners on Facebook Reels. - **Search:** Facebook and Instagram search results. - **Apps and sites:** Audience Network's native, banner, interstitial and rewarded video ads in partner apps. Two newer placements matter in 2026. Threads opened to all eligible advertisers worldwide in April 2025 and is on by default. WhatsApp Status ads, announced in June 2025, are still rolling out gradually. Meta also retired ads in the Messenger inbox in late 2025. Meta recommends **Advantage+ placements**, which let delivery spread budget across all of them and shift it to wherever results cost least. It is usually the right default, as long as you give each placement creative that fits it, above all vertical 9:16 versions for Stories and Reels. ## How the ad auction works Each time someone could see an ad, Meta runs an auction, and the ad with the highest **total value** wins. Meta defines total value as the bid multiplied by the estimated action rate, plus ad quality. In Meta's words, "ads with the highest bid don't always win." - **Bid:** what you're willing to pay for the result you optimise for, set directly or through a bid strategy. - **Estimated action rate:** how likely this person is to take that action, predicted by Meta's models. - **Ad quality:** feedback from people who see the ad, and signals of low quality such as engagement bait or withheld information. A relevant ad with a lower bid can beat a weaker ad with a higher one, and it usually pays less for the win. That is why creative quality shows up directly in your costs. ## Campaigns, ad sets and ads Meta campaigns have three levels: | Level | What you set | | --- | --- | | Campaign | The objective, and optionally an Advantage+ campaign budget shared across ad sets | | Ad set | Audience, placements, budget and schedule, the conversion event to optimise for, and the bid strategy | | Ad | Format, creative, text, call to action and destination | With **Advantage+**, Meta automates much of this. Advantage+ sales, app and leads campaigns run the whole setup end to end. Inside any campaign, Advantage+ audience treats your targeting as suggestions (you can still set hard limits such as minimum age and location), and Advantage+ creative can adapt your assets to each placement, from cropping to generating variations. ## Measurement with the Pixel and Conversions API The **Meta Pixel** is a snippet on your website that reports events such as page views, sign-ups and purchases. Browsers and ad blockers drop some of those events, so Meta also offers the **Conversions API**, which sends the same events from your server. Meta recommends using both. When the browser and the server report the same event with the same event name and event ID within 48 hours, Meta counts it once. You manage all of this in Events Manager, which also shows an Event Match Quality score for how well your events match people on Meta. Attribution changed in 2026. Since March, click-through attribution only counts link clicks, and other interactions such as saves and shares sit in a separate engage-through window. Compare periods with care across that change. ## Budgets, bidding and the learning phase - **Budgets:** a daily budget is an average. Meta can spend up to 75% more on a given day, but never more than seven times the daily budget in a week. A lifetime budget covers the whole run. For most ads billed on impressions the minimum is about $1 a day. - **Bid strategies:** Highest volume (the default), Cost per result goal, ROAS goal and Bid cap. - **Learning phase:** after launch or a significant edit, an ad set needs about 50 optimisation events in a week before delivery settles. If it can't get there, Ads Manager shows "Learning limited". The usual fixes are more budget, fewer ad sets, or a conversion event higher up the funnel. ## "Sponsored" is now "Ad" Meta has been replacing the "Sponsored" label on ads with "Ad". Instagram switched in March 2026 and Facebook has been testing the same change. Nothing changes for advertisers, but screenshots and brand guidelines that show "Sponsored" are going out of date. ## How to get started 1. **Set up the basics:** a Meta business portfolio, an ad account and a Facebook page. Add your Instagram account if you have one. 2. **Install tracking:** the Pixel on your site, plus the Conversions API from your server or platform. Test the events in Events Manager. 3. **Add a catalog** if you sell products, so you can run collection and catalog ads. 4. **Choose one objective** and one conversion event you can realistically get 50 of each week. 5. **Make creative for each format and placement,** starting with a 4:5 image and a 9:16 video. 6. **Launch with Advantage+** and leave it alone through the learning phase. 7. **Review weekly:** keep the ads that win, replace the ones that don't, and scale budget where results hold. If you'd rather hand it over, our [Meta Ads](/services/meta-ads) service covers the whole loop: the plan, creative for every format, landing pages and Instant Experiences, and Pixel and Conversions API tracking. For ads inside AI answers, see our guide to [ChatGPT ads](/insights/what-are-chatgpt-ads). ## Common questions ### Which format works best? There is no single winner. Most accounts do best with a mix: images and short vertical videos for the main offer, and carousels or collections for product ranges. Advantage+ then shows each person the version most likely to work. ### Can I still target specific interests? Yes, but Meta treats them more loosely than it used to. With Advantage+ audience, interests and demographics are suggestions, and detailed targeting exclusions were removed in 2025. Custom audiences built from your own customers and website visitors are still the most reliable signal. ### How long does ad review take? Most ads are reviewed within 24 hours. Ads about financial products, employment, housing or social issues fall under special ad categories, which limit targeting options. ### Do I need both the Pixel and the Conversions API? You can run with the Pixel alone, but you'll miss conversions that browsers block. Running both, deduplicated by event ID, gives Meta's delivery more complete data and you more accurate reporting. --- Sources: [Meta Ads Guide](https://www.facebook.com/business/ads-guide/update), [About ad placements](https://www.facebook.com/business/help/407108559393196), [How Meta delivers ads](https://www.facebook.com/business/news/good-questions-real-answers-how-does-facebook-use-machine-learning-to-deliver-ads), [About the learning phase](https://www.facebook.com/business/help/112167992830700), [Deduplicating Pixel and server events](https://developers.facebook.com/docs/marketing-api/conversions-api/deduplicate-pixel-and-server-events/), [Meta Advantage+](https://www.facebook.com/business/ads/meta-advantage-plus), [Meta Q2 2026 results](https://investor.atmeta.com/investor-news/press-release-details/2026/Meta-Reports-Second-Quarter-2026-Results/default.aspx), [Click attribution update](https://www.facebook.com/business/news/click-attribution) and [MediaPost on the "Ad" label](https://www.mediapost.com/publications/article/413532/meta-shifting-advertising-labeling-from-sponsored.html). Details reflect Meta's products as of September 2026 and may change.