Blended ROAS (Return on Ad Spend) measures total revenue generated per dollar of paid media spend, while MER (Marketing Efficiency Ratio) measures total revenue against total marketing spend (inclusive of paid and organic efforts). Both provide a holistic view of marketing effectiveness, transcending channel-specific metrics.
Here's how to calculate and interpret these crucial metrics:
1. Aggregate All Revenue Data: Consolidate all revenue from your business. This typically comes from your e-commerce platform (e.g., Shopify, Magento), CRM (e.g., Salesforce, HubSpot), or internal sales systems. Ensure you use a consistent definition, such as Gross Merchandise Value (GMV) or Net Revenue (after returns and discounts). For example, if your e-commerce platform reports $1,250,000 in sales for the month.
2. Aggregate All Paid Media Spend: Sum up all expenditures across all paid media channels. This includes Meta Ads (Facebook/Instagram), Google Ads (Search, Display, YouTube), programmatic platforms (e.g., DV360, The Trade Desk), TikTok Ads, Pinterest Ads, LinkedIn Ads, and any affiliate marketing commissions. Use the total reported spend from each platform's dashboard or API. For instance, if your total paid spend for the month is $250,000.
3. Aggregate All Total Marketing Spend (for MER): For MER, broaden your scope to include all marketing-related costs. This encompasses your total paid media spend, agency fees, content creation costs, SEO tool subscriptions, email marketing platform fees, influencer payments, and any salaries directly attributable to marketing personnel. If your total paid media spend is $250,000 and other marketing costs (salaries, tools, content) are $75,000, your total marketing spend is $325,000.
4. Calculate Blended ROAS: Divide your total aggregated revenue by your total paid media spend.
Formula: Blended ROAS = Total Revenue / Total Paid Media Spend
Example: $1,250,000 (Total Revenue) / $250,000 (Total Paid Media Spend) = 5.0x
5. Calculate MER: Divide your total aggregated revenue by your total marketing spend.
Formula: MER = Total Revenue / Total Marketing Spend
Example: $1,250,000 (Total Revenue) / $325,000 (Total Marketing Spend) = 3.85x
A simple Python script can automate this calculation:
```python
total_revenue = 1250000
total_paid_media_spend = 250000
total_other_marketing_spend = 75000
blended_roas = total_revenue / total_paid_media_spend
mer = total_revenue / (total_paid_media_spend + total_other_marketing_spend)
print(f"Blended ROAS: {blended_roas:.2f}x")
print(f"MER: {mer:.2f}x")
```
6. Interpretation: Blended ROAS indicates the overall efficiency of your paid advertising efforts, regardless of individual channel performance. MER provides a broader view of your entire marketing department's contribution to revenue, considering all expenditures. A declining trend in either metric signals a need to re-evaluate your marketing strategy and budget allocation.
| Metric | Focus | Calculation | Primary Use Case |
| :-------------- | :-------------------------- | :---------------------------------------- | :-------------------------------------------------- |
| Blended ROAS | Paid Media Efficiency | Total Revenue / Total Paid Media Spend | Assessing overall paid channel performance |
| MER | Total Marketing Efficiency | Total Revenue / Total Marketing Spend | Evaluating holistic marketing department ROI & budget |