Calculating Marketing ROI Across All Channels

Most small businesses measure marketing performance by a single metric: ROAS (Return on Ad Spend) for paid channels, or open rate and click rate for email. These metrics are useful but incomplete.

ROAS tells you how much revenue a campaign generated for every £1 spent — but it does not tell you the margin on that revenue, whether the customers acquired will return, or what you paid for fulfilment and returns. A 4× ROAS campaign that attracts high-return, low-margin customers may be less valuable than a 2.5× ROAS campaign that attracts low-return, high-LTV buyers.

AskBiz builds a complete marketing ROI picture by connecting ad spend to actual margin-adjusted revenue and long-run customer value.

For AskBiz to calculate marketing ROI, it needs both your spend data and your revenue data.

Revenue data is imported from your connected sales platforms (Shopify, Amazon, etc.).

Spend data comes from:

• Google Ads: connect via Settings → Integrations → Google Ads
• Meta Ads (Facebook/Instagram): connect via Settings → Integrations → Meta Ads
• TikTok Ads: connect via Settings → Integrations → TikTok Ads
• Other channels: enter spend manually in Finance → Marketing Spend → Manual Entry, or upload monthly via CSV

Once connected, AskBiz combines spend and revenue data to calculate ROI at the channel, campaign, and ad set level.

Go to Marketing → ROI Dashboard to see:

• Revenue by channel: total revenue attributed to each marketing channel
• Spend by channel: total spend in each channel in the period
• ROAS: revenue ÷ spend for each channel
• Margin-adjusted ROAS: (revenue × gross margin %) ÷ spend — the true return after product costs
• CAC by channel: total spend ÷ new customers acquired
• LTV:CAC ratio by channel: 12-month customer LTV ÷ CAC
• Blended marketing efficiency ratio: total gross profit from marketing-attributed revenue ÷ total marketing spend

The Blended Marketing Efficiency Ratio (MER) is the most useful single number for evaluating your overall marketing performance — a MER above 3× is strong for most eCommerce businesses.

Sort the ROI dashboard by Margin-adjusted ROAS (not headline ROAS) to rank channels by true return.

Common findings:

• Email marketing typically has the highest ROI (low cost, high conversion) — if email is not in your top 2 channels by margin-adjusted ROAS, your email programme needs investment
• Organic search (SEO) has near-zero marginal cost — its ROI is very high once measured against content and agency costs rather than per-click spend
• Paid social often has lower ROI than expected once returns, low-margin impulse buyers, and attribution inflation are accounted for
• Paid search tends to have strong ROI for branded terms and category-specific queries; weaker ROI for broad brand awareness campaigns

The goal is not to cut low-ROI channels but to reallocate marginal budget from lower-ROI to higher-ROI channels until diminishing returns equalise across channels.

Use AskBiz to set a target MER (Marketing Efficiency Ratio) or blended ROAS for each channel and track performance against it.

To set targets:

1. Go to Marketing → ROI Dashboard → Set Targets

2. Enter your target MER or ROAS for each channel

3. Set the period (monthly or quarterly)

AskBiz will alert you in your Daily Brief when any channel falls below its target for two consecutive weeks — giving you time to investigate and adjust before budget is wasted.

Review your targets quarterly as your channel mix, product mix, and margin profile evolve.