Facebook and Instagram both run through Meta Ads Manager, which means the targeting, bidding and reporting infrastructure is identical. The real differences come down to audience demographics, ad format strengths and where your specific customers are most likely to engage. For some businesses, Facebook delivers cheaper conversions. For others, Instagram drives stronger engagement and brand recall. Most advertisers get the best results running both, but with different creative and different expectations for each.
At Gorilla Marketing, we manage Meta advertising campaigns across both platforms for e-commerce and lead generation clients. We’ve seen first-hand how the same budget, targeting and offer can produce completely different results depending on which platform carries the spend. This guide breaks down the practical differences so you can allocate your budget based on performance data, not assumptions.
How Do Facebook and Instagram Audiences Differ?
The single biggest factor in choosing between these platforms is where your target customers actually spend their time. Both sit under the Meta umbrella, but the user bases are distinct.
Facebook’s core audience skews older. The platform’s strongest demographic sits between 25 and 54, with particularly high engagement among 35-44 year olds. It remains the dominant social platform for reaching parents, homeowners, professionals and decision-makers in established careers. Facebook also has broader geographic reach in the UK, particularly outside major cities.
Instagram’s audience skews younger, with peak usage among 18-34 year olds. It’s a visually-led platform where users actively browse, discover and engage with brands. Instagram over-indexes for fashion, beauty, food, travel, fitness and lifestyle categories. But it’s not just a young person’s platform; the 35-44 bracket has grown significantly over the past two years.
The overlap matters too. Many users are active on both platforms, which means your ads can reach the same person in different contexts. Someone scrolling Facebook during a lunch break is in a different mindset to someone browsing Instagram Stories before bed. That context shapes how they respond to your ads.
Cost Comparison: CPC, CPM and What Actually Matters
Cost benchmarks for Facebook and Instagram vary significantly by industry, objective and time of year. Quoting exact figures is misleading because your actual costs depend on your targeting, creative quality, competition and bidding strategy. That said, some general patterns hold.
Facebook tends to deliver lower cost-per-click (CPC) for link clicks and traffic campaigns. Its larger audience pool means more inventory, which typically keeps CPMs (cost per thousand impressions) lower. For lead generation and conversion campaigns targeting broad audiences, Facebook often comes in cheaper on a per-result basis.
Instagram CPMs tend to run higher because the ad placements are more visually prominent and competition for attention is fierce. However, higher CPMs don’t necessarily mean worse value. Instagram ads often generate stronger engagement rates, higher click-through rates on visual products and better brand recall. If your goal is awareness or consideration rather than direct response, Instagram’s higher CPM can deliver more impact per impression.
The real metric that matters is cost per acquisition or cost per lead, not CPC or CPM in isolation. We regularly see campaigns where Instagram’s higher CPM produces a lower cost per conversion because the creative format and audience alignment work harder.
Ad Formats: What Can You Run Where?
Both platforms share some formats through Meta Ads Manager, but each has exclusive placements and format strengths.
Facebook Ad Formats
News Feed ads – the workhorse format. Image, video or carousel ads in the main feed. Good for all objectives.
Right column ads – desktop only, smaller format. Cheap impressions, lower engagement. Best for retargeting where brand recognition is already established.
Marketplace ads – appear alongside organic Marketplace listings. Strong for e-commerce, particularly second-hand goods, furniture, vehicles and local services.
Video ads – in-feed and in-stream (mid-roll in longer videos). Facebook’s video inventory is enormous.
Lead forms – native lead generation forms that pre-fill user data. High conversion rates because users don’t leave the platform.
Messenger ads – deliver ads directly into Messenger or drive conversations. Works well for service businesses where a quick chat converts.
Instagram Ad Formats
Feed ads – image, video or carousel in the main feed. Visually rich and high-impact.
Stories ads – full-screen vertical format between organic Stories. One of Instagram’s strongest placements for direct response and awareness.
Reels ads – full-screen vertical video ads within the Reels feed. Growing inventory and strong engagement, particularly with younger audiences.
Explore ads – appear in the Explore tab where users actively browse for new content. Good for discovery and prospecting.
Shopping ads – tag products directly in images and videos. Users can browse and purchase without leaving the app. A powerful format for e-commerce PPC.
Shared Formats
Carousel ads, collection ads and dynamic product ads run across both platforms. The creative dimensions and specs are identical, but the context changes. A carousel showcasing product features plays differently in Facebook’s text-heavy feed compared to Instagram’s visual-first environment.
Targeting: Same Engine, Different Context
Here’s what most comparison articles get wrong. Facebook Ads and Instagram Ads use the same targeting system. You build audiences in Meta Ads Manager, and those audiences can be deployed to either platform (or both). Custom audiences, lookalikes, interest targeting, demographic filters, behavioural segments – all identical.
The difference isn’t in who you can target. It’s in who responds.
The same interest-based audience might perform very differently on each platform because user behaviour and content consumption patterns differ. Someone interested in interior design on Facebook might click a blog link. The same person on Instagram might save a product image or visit a shop. Same audience definition; different action.
This is why retargeting ads work particularly well in a cross-platform strategy. You can prospect on one platform and retarget on the other, catching users in a different context and mindset.
When to Use Facebook Ads
Facebook is typically the stronger platform when:
You’re targeting over-35 demographics. Facebook’s user base is older and broader. If your customers are homeowners, parents, B2B decision-makers or professionals, Facebook gives you better reach.
You’re running lead generation campaigns. Facebook’s native lead forms convert well, and the platform’s News Feed is built for content consumption. Users are more willing to engage with longer-form content and fill out forms.
You’re promoting content or driving website traffic. Link-click campaigns perform well on Facebook because the platform’s feed naturally accommodates external links. Users are accustomed to clicking through to articles, landing pages and offers.
Budget is tight. Lower CPMs mean your budget goes further in terms of raw reach. For businesses testing paid social for the first time, Facebook often delivers faster learning at lower cost.
You’re a local service business. Facebook’s community features, local targeting and Marketplace placement make it strong for businesses serving a specific geographic area.
When to Use Instagram Ads
Instagram tends to outperform when:
Your product is visual. Fashion, beauty, food, interiors, travel, fitness. If your product photographs well, Instagram’s format gives it room to shine.
You’re targeting 18-34 year olds. Instagram is the primary social platform for this demographic. If your customer base skews young, you’ll find better engagement and lower funnel costs here.
Brand awareness is a priority. Instagram’s immersive formats (Stories, Reels, Explore) create stronger brand recall than Facebook’s text-mixed feed. Users are in a browsing and discovery mindset, which makes them more receptive to new brands.
You’re running e-commerce campaigns. Instagram Shopping, product tags and the visual catalogue format create a seamless path from discovery to purchase. Shoppable posts blur the line between organic browsing and paid advertising.
You want higher engagement rates. Instagram consistently delivers higher engagement per impression than Facebook. If engagement metrics matter for your brand strategy, Instagram is the stronger bet.
When to Run Both (and How to Split Budget)
For most businesses spending more than a few hundred pounds a month on Meta ads, running both platforms delivers better results than picking one. The question isn’t whether to use both, but how to allocate budget between them.
A common starting approach is a 60/40 split weighted toward the platform that better matches your core audience. For a B2B software company targeting senior managers, that might mean 60% Facebook, 40% Instagram. For a DTC fashion brand, the reverse.
But don’t set it and forget it. The right split changes based on:
Campaign objective – awareness campaigns might favour Instagram; conversion campaigns might favour Facebook
Creative assets – if you have strong video and photography, lean into Instagram’s visual placements
Seasonality – Instagram engagement tends to spike around visual events (fashion weeks, holidays, summer) while Facebook holds steadier year-round
Performance data – let the numbers guide you. If Instagram is delivering conversions at half the cost, shift budget accordingly
Meta’s Advantage+ placements will automatically distribute your budget across both platforms based on performance signals. This works well for established campaigns with enough conversion data. For newer campaigns or smaller budgets, manual placement selection gives you more control and better learning.
Industry Recommendations
E-commerce
Run both. Use Instagram Ads for prospecting with visual creative (Reels, Stories, Shopping ads) and Facebook Ads for retargeting, lookalike audiences and catalogue-driven campaigns. Instagram typically wins at the top of funnel; Facebook often converts cheaper at the bottom.
B2B and Professional Services
Facebook first. The older demographic, News Feed format and lead form capabilities make it the stronger platform for B2B. Instagram can supplement for brand building, particularly if your brand has a strong visual identity or company culture worth showcasing.
Local Services
Facebook. Marketplace ads, local awareness campaigns and community-based targeting give Facebook a clear edge for plumbers, solicitors, dentists, restaurants and other local businesses. Instagram can support brand awareness, but Facebook drives more direct enquiries.
Health, Beauty and Lifestyle
Instagram first. The visual-first format, influencer ecosystem and shopping capabilities make Instagram the natural home for these categories. Facebook supports broader reach and retargeting.
How to A/B Test Across Platforms
Don’t guess which platform works better. Test it.
The cleanest approach is to run identical campaigns on each platform separately, rather than using a combined campaign with automatic placements. This gives you clear, platform-level performance data.
Set up the test properly:
Create two campaigns with the same objective, budget, targeting and schedule
Use the same creative assets in both (adjust dimensions for each placement, but keep the messaging identical)
Run them simultaneously for at least 7-14 days to get past the learning phase
Compare on the metric that matters to your business: cost per lead, cost per purchase, ROAS, or cost per landing page view
What to watch for:
Learning phase distortion – Meta’s algorithm needs roughly 50 conversion events per ad set per week to optimise effectively. If your budget is too small to hit that threshold on both platforms, focus on one at a time.
Creative fatigue – Instagram users tend to fatigue on creative faster than Facebook users because the platform is more visually saturated. Refresh Instagram creative more frequently.
Attribution differences – the same user might see your ad on Instagram and convert via Facebook (or vice versa). Meta’s cross-platform attribution captures some of this, but it’s not perfect. Look at blended performance alongside platform-specific numbers.
Common Mistakes to Avoid
Leaving default placements on without checking performance. Advantage+ placements can work, but they often over-allocate to cheap, low-quality inventory (Audience Network, right column) while underserving the placements that actually convert. Review placement breakdowns regularly.
Using the same creative for both platforms. A landscape image with text overlay that works on Facebook’s News Feed looks cramped in Instagram Stories. Adapt your creative for each placement, even if the core message stays the same.
Judging Instagram by Facebook’s metrics. If you’re comparing raw CPC, Facebook will usually win. But CPC doesn’t capture the full picture. Compare platforms on cost per meaningful action, not cost per click.
Ignoring frequency. Ad fatigue hits harder on Instagram because users scroll faster and expect fresh content. If your frequency creeps above 3-4 on Instagram, you’re likely wasting budget on diminishing returns.
Not testing vertical video. Stories and Reels are Instagram’s fastest-growing ad placements, and vertical video performs increasingly well on Facebook too. If you’re still running static images exclusively, you’re leaving performance on the table.
Picking the Right Platform for Your Budget
The question isn’t really Facebook or Instagram. It’s about understanding where your specific audience engages, what creative formats play to your strengths and which platform delivers the results that matter to your business. The data is there; you just need to structure your campaigns to surface it.
If you’re running Meta ads and want a clearer picture of where your budget should sit, Gorilla Marketing can help. We manage paid social campaigns across both platforms for e-commerce and lead generation clients, and we optimise based on what the numbers actually show, not platform preferences. Get in touch to talk about your campaign.
