Weekly MER Review Template for Shopify DTC Teams

Why Weekly, Not Monthly

Monthly MER reviews arrive too late to correct channel decay. By the time a brand sees a 2.8 MER in month-end reporting, 3-4 weeks of underperforming spend have already occurred. Weekly snapshots catch deterioration within 5-7 days, enabling pause or budget reallocation before compounding losses.

Weekly review also isolates day-of-week and promotional calendar effects. A brand running a flash sale Thursday through Sunday will see inflated MER that week; weekly tracking prevents misinterpreting promotional lift as channel improvement.

MER Thresholds by Channel and Stage

Thresholds vary by channel maturity and brand profitability. New channels (first 4 weeks) operate under different rules than mature channels.

Mature paid search (Google Shopping, brand keywords): 3.5 - 5.0+ MER. Threshold for pause: below 2.8.
Mature paid social (Meta, TikTok): 2.5 - 4.0 MER. Threshold for pause: below 2.0.
New channel pilot (first 4 weeks): Accept 1.5 - 2.2 MER if volume is under 10% of weekly spend. Kill if no improvement by week 4.
Seasonal/promotional channel (email, SMS): 4.0 - 8.0+ MER. Threshold for pause: below 3.0.
Organic (owned): Measure separately; not subject to MER thresholds (no ad spend denominator).

Weekly Review Checklist

Run this review every Monday morning using prior week data (Sunday through Saturday). Allocate 20 - 30 minutes.

Pull revenue, COGS, and ad spend by channel for the past 7 days.
Calculate gross profit: (Revenue - COGS). Use rolling 13-week average gross margin if daily margin varies.
Divide gross profit by total ad spend for each channel. Record MER and compare to prior week and 4-week rolling average.
Flag channels where MER dropped >15% week-over-week or sits below threshold.
Check for external factors: platform algorithm changes, bid increases, audience saturation, competitor activity, or promotional calendar shifts.
Document decision: hold, increase budget, decrease budget, pause, or test new creative/audience.
Update a shared tracker (Google Sheet or ops tool) with MER, decision, and rationale.

Common Failure Modes and Fixes

MER decline often stems from predictable causes. Diagnosis requires isolating spend and revenue movement.

Declining MER + flat revenue + rising spend: Audience saturation or bid inflation. Action: Pause underperforming segments, test new audiences, or reduce daily budget 10-15% to reset.
Declining MER + rising revenue + rising spend: Margin compression (COGS increase or discounting). Action: Verify COGS and promotional calendar; MER may be correct signal that profitability is eroding.
Declining MER + flat spend + declining revenue: Creative fatigue or platform decay. Action: Refresh creative, test new hooks, or pause and restart campaign.
Volatile MER week-to-week (>20% swings): Insufficient volume or attribution lag. Action: Aggregate to 2-week rolling average; do not make spend decisions on single-week noise.
MER above threshold but declining trend: Early warning. Action: Reduce spend 5-10% to test elasticity; if MER stabilizes, hold; if MER improves, continue reduction.

Attribution and Timing Adjustments

MER calculations depend on attribution window and conversion lag. Misalignment creates false signals.

Use a consistent attribution window (7-day click, 1-day view, or 30-day click depending on brand and category). Do not mix windows week-to-week. If platform default is 28-day, standardize reporting to 28-day across all channels.

Account for conversion lag: e-commerce orders placed Sunday may not ship until Wednesday. Weekly MER includes orders from prior week's spend. To isolate true weekly causality, use a 2-week rolling average or lag revenue by 2-3 days.

For subscription or high-AOV brands, use a 30-day rolling MER to smooth order timing variance.

Escalation Rules

Define when to escalate MER decline to leadership or pause spend without waiting for next week's review.

If any channel MER drops below 1.5 in a single day (calculated daily), pause that channel immediately and investigate.
If total brand MER (all channels combined) drops below 2.0 for 2 consecutive weeks, trigger a full audit of COGS, attribution, and platform settings.
If a mature channel (>$5k weekly spend) declines >25% MER in one week, reduce spend by 25% and hold for 3 days before re-evaluating.
If a new channel pilot reaches week 4 with MER below 1.8, kill the pilot and reallocate budget.

Template Outputs and Handoff

Document weekly MER review in a standardized format to enable pattern recognition and accountability.

Record: date, channel, MER, prior week MER, 4-week average MER, spend, revenue, gross profit, decision, and rationale. Share with finance and marketing leads by Tuesday morning.

Use outputs to inform monthly budget allocation and quarterly channel strategy. Patterns (e.g., Meta MER declining every Q4) inform seasonal planning.

Questions

FAQ

Should MER include organic or owned channels?

No. MER is defined as gross profit per paid marketing dollar. Organic (search, direct, referral) and owned (email, SMS without paid promotion) have no ad spend denominator. Track them separately as ROAS or contribution margin. If running paid email or SMS campaigns, include those spend in MER calculation.

What if gross margin varies daily (e.g., bundles vs. single items)?

Use a rolling 13-week average gross margin percentage applied to weekly revenue. This smooths product mix variance and prevents false MER swings from a single high-margin or low-margin day. Recalculate the 13-week average every Monday.

How do I account for platform attribution differences (Meta vs. Google)?

Standardize to one attribution window across all platforms (e.g., 7-day click for all). Use platform-native reporting (Meta Ads Manager, Google Ads) for internal MER tracking, but reconcile weekly against your actual revenue and COGS in your financial system. If platforms disagree on revenue by >10%, audit UTM tagging and pixel implementation.

When should I pause a channel based on MER alone?

Pause only if MER is below threshold AND spend is >5% of weekly budget AND the decline persists for 2+ weeks. Do not pause on a single week of noise. Exception: if daily MER drops below 1.5 (indicating near-zero profit), pause immediately and investigate attribution or COGS errors before resuming.

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Weekly MER Review: Thresholds and Failure Modes