Glossary / Advertising

Return on Ad Spend (ROAS)

Return on Ad Spend (ROAS) measures the revenue generated for every pound spent on advertising. A ROAS of 4x means you earn £4 in revenue for every £1 spent on ads.

Definition

Return on Ad Spend (ROAS) measures the revenue generated for every pound spent on advertising. A ROAS of 4x means you earn £4 in revenue for every £1 spent on ads.

Formula: ROAS = Revenue from Ads ÷ Cost of Ads

Understanding ROAS

ROAS is the primary metric for evaluating advertising performance in ecommerce. It tells you whether your ad campaigns are generating enough revenue to justify their cost. However, ROAS measures revenue, not profit. A 4x ROAS sounds impressive, but if your margins are only 20%, you are barely breaking even on ad spend. Smart ecommerce operators set ROAS targets based on their margin structure, not arbitrary benchmarks.

ROAS Formula

ROAS = Revenue from Ads ÷ Cost of Ads

Worked Example

Example

You spend £2,000 on Google Shopping ads and generate £8,000 in attributable revenue. Your ROAS is £8,000 ÷ £2,000 = 4x. For every £1 spent, you earned £4 in revenue. Whether this is profitable depends on your margins.

Why ROAS Matters for Ecommerce

ROAS determines whether scaling ad spend will grow your business or drain it. Without tracking ROAS, you are flying blind on your biggest variable expense. It also helps you allocate budget between channels and campaigns based on performance.

Common Mistakes

01

Targeting a ROAS number without knowing what ROAS you need to be profitable

02

Comparing ROAS across platforms without accounting for different attribution models

03

Treating ROAS as a profit metric when it only measures revenue efficiency

How StoreLyst Helps with ROAS

StoreLyst connects your ad spend to actual profit, not just revenue. You see profit-adjusted ROAS (pROAS) that accounts for COGS and fees, so you know exactly which campaigns are truly profitable.

Learn more about Google Ads →

Frequently asked questions about ROAS

What is a good ROAS for ecommerce?

It depends entirely on your margins. A store with 60% gross margins can be profitable at 2x ROAS, while a store with 25% margins needs 5x or higher. Calculate your break-even ROAS first: Break-Even ROAS = 1 ÷ Gross Margin Percentage.

What is the difference between ROAS and ROI?

ROAS measures revenue relative to ad spend only. ROI (Return on Investment) measures net profit relative to total investment including all costs. ROAS is a top-line metric; ROI is a bottom-line metric. Both are useful for different decisions.

Why does my ROAS look different on Google vs Shopify?

Different platforms use different attribution models. Google may credit a sale to a click that happened 30 days ago, while Shopify attributes it to the last click. Neither is wrong; they measure differently. Use one consistent source for ROAS decisions.

How do I improve my ROAS?

Improve ad targeting to reach higher-intent audiences, optimise product feeds for relevance, improve landing page conversion rates, increase AOV through upsells, and regularly prune underperforming keywords or audiences. Better creative also drives higher click-through and conversion rates.

Track ROAS automatically with StoreLyst

Stop calculating in spreadsheets. Get real-time roas tracking for your Shopify store.