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Paid Social Advertising·Lesson 5 of 5

Measuring ROAS

Spending money on ads without measuring the return is gambling. ROAS (Return on Ad Spend) is the metric that tells you whether your paid social campaigns are profitable. This lesson covers how to track, calculate, and act on your ROAS numbers.

What is ROAS?

ROAS measures how much revenue you earn for every dollar spent on advertising. The formula is simple:

ROAS = Revenue from Ads / Ad Spend

If you spent $1,000 on ads and generated $4,000 in revenue, your ROAS is 4.0 (or 400%). For every dollar spent, you earned four dollars back.

What is a good ROAS? It depends entirely on your margins:

  • E-commerce with 50% margins: A 2.0 ROAS means you break even. You need 3.0+ to be profitable.
  • SaaS with high lifetime value: A 1.5 ROAS on first purchase might be profitable if customers stay for 12+ months.
  • Lead generation: ROAS is harder to calculate directly. Focus on cost per lead and lead-to-customer conversion rate instead.

Know your break-even ROAS before you launch a campaign. This is the minimum ROAS needed to cover your product costs, fulfillment, and ad spend without losing money.

Conversion Tracking Setup

Accurate ROAS measurement requires proper conversion tracking. Without it, you are flying blind.

Essential tracking components:

  1. Platform pixel — Meta Pixel, LinkedIn Insight Tag, TikTok Pixel installed on your website (covered in Lesson 2)
  2. Conversion events — define what counts as a conversion: purchase, lead form submission, free trial signup, app install
  3. Conversion value — pass the actual purchase value to the pixel so you can calculate revenue, not just count conversions
  4. Server-side tracking — as browser privacy features block more client-side tracking, implement server-side event APIs (Meta Conversions API, Google Enhanced Conversions) for more accurate data

Testing your tracking:

  • Use the Meta Pixel Helper or equivalent browser extension to verify events fire correctly
  • Make a test purchase or form submission and confirm it appears in your ad platform's events dashboard
  • Compare ad platform reported conversions against your own sales data — they should roughly match (within 10-20%)

Attribution Models

Attribution answers the question: "Which ad gets credit for a conversion?" This is more complex than it sounds because a customer might see multiple ads before converting.

Common attribution models:

  • Last-click — the last ad clicked before conversion gets 100% credit. This is the default for most platforms and favors bottom-of-funnel campaigns.
  • First-click — the first touchpoint gets 100% credit. This favors top-of-funnel awareness campaigns.
  • Linear — credit is split equally across all touchpoints. A customer who saw 4 ads gives each 25% credit.
  • Time-decay — touchpoints closer to the conversion get more credit. The ad seen the day before purchase gets more credit than the ad seen two weeks ago.
  • Data-driven — the platform's algorithm assigns credit based on which touchpoints had the most impact. Available in Google Analytics 4 and some ad platforms.

Attribution windows also matter. Meta's default is 7-day click, 1-day view — meaning a conversion is attributed to an ad if someone clicked within 7 days or viewed within 1 day before converting. Longer windows attribute more conversions but with less certainty.

For most businesses, start with the platform's default attribution and compare it against your own first-party data (actual sales records) to gauge accuracy.

Cost Per Result Metrics

Beyond ROAS, track these cost metrics to evaluate campaign efficiency:

  • CPC (Cost Per Click) — total spend divided by link clicks. Benchmark: $0.50-2.00 for most industries on Meta.
  • CPM (Cost Per Mille) — cost per 1,000 impressions. Benchmark: $5-15 on Meta, higher on LinkedIn ($8-30).
  • CPL (Cost Per Lead) — total spend divided by leads generated. Varies dramatically by industry ($5-200+).
  • CPA (Cost Per Acquisition) — total spend divided by customers acquired. Your most important cost metric for conversion campaigns.

Track these metrics daily during active campaigns. Sudden increases often signal audience fatigue, increased competition, or creative exhaustion.

When to Kill or Scale a Campaign

Knowing when to cut losses and when to invest more is the most important skill in paid social.

Kill a campaign when:

  • ROAS is below your break-even point after the learning phase (50+ conversions or 7+ days)
  • Cost per result is increasing week-over-week despite optimization efforts
  • Frequency is above 3-4 (the same people are seeing your ad too many times)
  • Creative is exhausted — CTR has dropped below 1% and continues declining
  • The audience is saturated — you have reached most of your target audience multiple times

Scale a campaign when:

  • ROAS is consistently above your target for 7+ consecutive days
  • Cost per result is stable or decreasing
  • There is still audience headroom (the estimated audience is much larger than the number reached)
  • Creative performance is steady (CTR and conversion rate are not declining)

The scaling process:

  1. Increase budget by 20-30% every 3-5 days on winning ad sets
  2. Duplicate winning ads into new audiences (horizontal scaling)
  3. Create new creative variations based on your best performers
  4. Monitor daily — scaling can cause temporary cost spikes that stabilize within 48 hours

Never set and forget. Paid social campaigns require active management. Check performance at least every 2-3 days and adjust based on data, not emotion. A campaign that was profitable last week may need new creative or audience adjustments this week.