Introduction: Why Facebook Ads is still a “gold mine” but easily becomes a “black hole” for budget?
Facebook Ads in Vietnam attracts more than 70 million users monthly. However, according to the report Digital 2024 Vietnam from DataReportal, average advertising cost increased 25% compared to 2023 due to fierce competition. Many SMEs “burn money” without results.
The article analyzes 7 real mistakes from agency experience serving 5,400 customers since 2017. You will learn the campaign checking framework and specific optimization checklist.
“70% Facebook Ads budget in Vietnam wasted due to wrong targeting” – DataReportal Digital 2024 Vietnam.
Mistake 1: Ignoring the specifics of Vietnamese user behavior
Misunderstanding Vietnamese customers' online time
Vietnamese people mainly online from 20h-23h and weekends. Running ads during European peak hours (morning in Vietnam) leads to low CTR. Highlands Coffee 2022 case: Reduced 40% costs when switching to 20h-22h slots.
According to SimilarWeb, Facebook Vietnam has completely different peak times from US/EU. Ignoring this causes CPM to skyrocket.
Not localizing content correctly to culture
Using US templates with too many emojis is seen as spam. Vinamilk Tet 2023 case: Increased 3x conversion when using Vietnamese family images instead of stock photos.
Checklist to check ad timing:
- Check Facebook Insights to see audience online hours
- Run A/B test on 3 time slots: 11h-13h, 20h-22h, 8h-10h morning
- If ROAS < 2.0, switch slots immediately
- Compare CTR Vietnam vs international templates
- Measure engagement rate by day of the week
Framework “3L Vietnam”: Local Time – Local Language – Local Culture
Applying this framework helps reduce 30-50% acquisition costs based on 5+ years of experience.
Mistake 2: Targeting too broad like “shooting into the sky”
Ignoring behavioral shopping targeting layer
Targeting only age + gender shows high reach but low conversion. Tiki 2021 Black Friday case: Layering “Engaged Shoppers” increased ROAS from 1.8 to 4.2.
According to Facebook Blueprint, behavior targeting is 3x more effective than demographic in SEA markets.
Not using high-quality Lookalike
Poor quality 1% lookalike from pixel only increases reach, not sales. Shopee case: Lookalike from “Add to Cart” performs 250% better than “Page View”.
Comparison table of targeting types:
| Type of Targeting | Advantages | Disadvantages | Suitable when |
|---|---|---|---|
| Broad Demographic | Large reach, low cost | Poor conversion, wasteful | Brand awareness |
| Interest-based | Higher relevance | High competition, expensive CPM | Average lead gen |
| Behavior + Lookalike | Highest ROAS | Need pixel data 30+ days | Ecommerce, retarget |
| Custom Audience | Best conversion | Small scale | Retargeting, VIP customers |
Checklist to build effective audience:
- Build pixel data with at least 1,000 events before scaling
- Layer maximum 3 conditions: Interest + Behavior + Device
- Test Lookalike 1%, 2%, 5% at the same time
- Exclude recent buyers to avoid cannibalization
- Measure Frequency cap < 3 times/day
Mistake 3: Creative copy-paste from international ineffective
Using stock photo instead of real Vietnamese photo
Vietnamese people recognize local brands through familiar contexts. Case Biti’s Hunter 2019: Real photo of Saigon streets increased engagement 5x compared to studio shot.
According to Nielsen Vietnam, authentic content increases trust 40% in the local market.
Headline and CTA not suitable for psychology
“Buy Now” is less effective than “Claim offer now”. Case Lazada 11.11: Localized Vietnamese CTA increased clicks 28%.
Creative optimization checklist:
- Test 4 formats: Carousel, 15s Video, Single Image, Collection
- Headline under 5 words, containing specific benefit
- Primary text < 100 characters, leading from problem → solution
- CTA button: “Buy now” instead of “Learn More”
- Video with Vietnamese text overlay
Mistake 4: Not setting up Attribution Window correctly
Default 7-day click causes misunderstanding ROAS
Vietnamese customers often research 14-28 days before buying. Case The Gioi Di Dong: Switching to 28-day view increased reported ROAS 180%.
Facebook's default 7-day click suits US/UK but not Vietnam.
Ignoring cross-device tracking
60% customers view on mobile, buy on desktop. Not enabling Cross-Device Under Cookies loses 35% conversion per FPT Shop 2023 case.
Checklist for attribution setup:
- Choose 28-day click + 1-day view for ecommerce
- Enable Cross-Device tracking in Events Manager
- Compare ROAS between attribution windows
- If ROAS < 1.5, check attribution immediately
- Measure multi-touch attribution with UTM
Mistake 5: Scaling incorrectly – Sudden budget increase
20% rule overlooked
Increasing budget >20%/day causes Facebook to reset learning phase. Case Guardian Vietnam: Scaled 15%/day kept CPA stable for 45 consecutive days.
Duplicate ad set instead of scaling winning ads
Meta recommends horizontal scaling (budget increase) instead of duplication. Case Senka skincare: Scaling budget increased ROAS 10% instead of duplication decreasing 25%.
Comparison table of scaling methods:
| Method | Advantages | Risks | Recommendations |
|---|---|---|---|
| Increase budget 50%/day | Fast | Learning phase reset, CPA spike | Avoid |
| 20% rule (Meta) | Most stable | Scale slowly | Campaign > 50m/month |
| Duplicate ad sets | Easy to do | Audience overlap 70% | Test small only |
| Expand audience | New reach | Quality score decreases |
Mistake 6: Ignoring iOS 14+ tracking limitations
Not installing SKAdNetwork correctly
From 2021, iOS 14+ only reports 50% conversion. Unilever Vietnam Case: Installing SKAN increased attribution accuracy by 65%.
“iOS 14+ reduces reported ROAS by 30-50% in SEA” – Facebook Business Blog 2023.
Over-relying on web pixel
Only 35% of iOS users have full web journey. Need to supplement with Server-side API as recommended by Meta.
Checklist to prevent iOS data loss:
- Install SKAdNetwork for all campaigns from 2022
- Enable Aggregated Event Measurement, prioritize Purchase
- Test Server-side tracking with CAPI
- Monitor iOS vs Android ROAS differential
- If iOS CPA is 2x higher → check immediately
Mistake 7: No systematic retargeting system
Ignoring cart abandoners (abandoned cart)
75% of Vietnamese carts are abandoned. Tiki Case: Retarget cart in first 72h increases recovery rate by 22%.
Retargeting too broad in time
View content retarget over 7 days is low effective. Shopee Case: 1-3 days for cart, 7 days for viewcontent.
Checklist to build retargeting funnel:
- Cart Abandoner: 1-72h, discount 10-20%
- Add to Cart: 1-7 days, free ship
- View Content: 1-3 days, social proof
- Past Buyer: 30-90 days, loyalty offer
- Setup frequency cap 3-5 times/week
Conclusion: 3-step Framework to check Facebook Ads today
1. Audit attribution + targeting (use checklist above). 2. Test 3 new creatives each week. 3. Scale only when ROAS stable for 7 days.
Effectiveness depends on product category, budget size and execution quality. Fashion ecommerce scales easier than B2B services. Monitor Meta Advantage+ campaigns as current alternative.
Start by checking 1 mistake you're making right now today.
