The Complete eCommerce Guide to Paid Media

Paid media is the fastest way to put your products in front of buyers who do not yet know you exist. Unlike SEO or organic social, which compound slowly, a paid campaign can drive qualified traffic on day one. For most growing stores that speed is the point: it lets you test products, find your best customers, and scale what works without waiting months for organic reach to build.

The catch is that paid media has become more expensive and more competitive every year. Average return on ad spend across eCommerce sat at roughly 2.87x in 2025, down around 4% year on year, and half of stores operate below a 2.0x return. Rising costs, privacy changes that weakened tracking, and more advertisers competing for the same attention have all squeezed margins. Throwing money at the platforms is no longer a strategy.

What separates profitable advertisers from the rest is rarely the creative or the bidding. It is the system behind the ad. The stores that win send their paid traffic into a well-built site, capture emails from people who do not buy on the first visit, and use retention to make each acquired customer worth far more than a single order. Paid media buys the first click. Everything after that decides whether it was worth it.

Percentage of revenue is a useful starting point, but it is a blunt instrument. The smarter way to set a paid media budget is to work backwards from your unit economics. If you know your average order value, your gross margin, and your customer lifetime value, you can calculate how much you can afford to pay to acquire a customer and still make money. That target cost per acquisition, not a generic percentage, should drive your spend.

Two stores with identical revenue can justify very different budgets. A brand selling consumable products with strong repeat purchase rates can afford to break even or even lose money on the first order, because retention pays it back. A brand selling one-off, low-margin products cannot. This is why lifetime value sits at the centre of every sound paid media plan, and why retention work quietly raises the ceiling on what you can spend to acquire.

A practical rule of thumb: start with a budget you can afford to lose while you learn, set a clear target return, and only scale spend on the campaigns that beat it. Increasing budget on a profitable campaign by 20% to 30% per week lets the platforms re-optimise without resetting their learning. If you want a structured view of where your current spend is leaking, our free eCommerce growth audit is a good place to start.

Meta, covering Facebook and Instagram, is the workhorse of eCommerce prospecting. Its strength is interruption: it shows your product to people who were not searching for it but who match the profile of your buyers. With a median ROAS around 1.86x and an average closer to 2.2x, Meta rarely posts the highest return on paper, but its scale and audience targeting make it the primary growth engine for most stores.

Meta returns are also seasonal. B2C eCommerce ROAS on Meta tends to climb to 4x to 5x during the Q4 peak, soften to 2x to 2.5x in the post-Christmas lull of January and February, and settle around 3x to 3.5x through the summer. Planning your budget around this pattern, rather than expecting flat performance, prevents the panic cuts that wreck campaign learning.

To get the most from Meta:

• Lead with creative. On Meta the ad itself is the main lever. Video and user-generated content that stops the scroll outperform polished studio shots, and you need a steady stream of fresh creative to fight fatigue.
• Use broad targeting. Meta’s algorithm now finds buyers better than manual interest stacking. Give it a clear conversion goal, strong creative, and room to learn rather than over-segmenting.
• Separate prospecting and retargeting. Cold audiences need different messaging from people who already viewed a product. Keep the budgets and creative distinct so you can read performance honestly.
• Feed the algorithm clean data. Server-side tracking through the Conversions API restores much of the signal lost to privacy changes and helps Meta optimise toward real purchases.

Where Meta interrupts, Google Shopping captures demand that already exists. When someone searches for a product, Shopping ads place your image, price, and store name directly in the results. Because that shopper has already declared intent, the returns are strong: Google Shopping posts a median ROAS around 5.0x, and Google Search overall sits near 5.17x, comfortably ahead of social platforms.

The trade-off is volume. Google Shopping can only reach people who are actively searching, so it cannot create demand the way Meta and TikTok can. Most stores treat Google as the reliable, high-return base of their paid mix and use social to generate the demand that later shows up as branded and category searches.

Success on Google Shopping is won in the product feed, not the campaign settings. The feed is the raw material the algorithm uses to match your products to searches, so:

• Optimise product titles with the words people actually search, leading with brand, product type, and key attributes like size or colour.
• Keep the feed clean and complete. Accurate prices, availability, GTINs, and high quality images directly affect how often and where your products show.
• Structure campaigns by margin and intent so you can bid more aggressively on your most profitable products and protect branded searches.
• Use Performance Max carefully. It can scale efficiently, but without guardrails it leans on branded traffic and obscures where the return is really coming from.

TikTok is the newest of the big three and the most misunderstood. Its median eCommerce ROAS sits around 1.41x, the lowest of the three platforms, which leads many stores to dismiss it. That is a mistake for the right products. TikTok excels at discovery and impulse: it can take a product from unknown to sold out in days, and certain categories such as beauty and personal care consistently reach 3.5x or higher.

TikTok Shop has also turned the platform into a checkout, not just a discovery channel. Shoppers can buy without leaving the app, which shortens the path from interest to purchase and makes the platform far more valuable for the right catalogue. For stores targeting younger audiences or selling visually demonstrable products, TikTok has moved from optional to important.

The platform rewards content that does not look like advertising. Native, creator-led video that fits the feed outperforms repurposed Meta assets, and partnering with creators is often more effective than producing ads in-house. TikTok sits naturally alongside your wider social commerce strategy, where paid and organic content reinforce each other. Treat its lower headline ROAS as the cost of buying demand and reach you cannot get anywhere else.

Benchmarks are a sanity check, not a target. Your own break-even ROAS, set by your margins and lifetime value, matters far more than any industry median. Still, knowing roughly where each platform lands helps you set expectations and spot when a campaign is genuinely underperforming. The figures below reflect 2025 cross-platform eCommerce data.

Read these as the platforms’ natural roles, not a league table. Google rewards captured intent with high efficiency but limited reach. Meta and TikTok cost more per pound returned because they are generating demand that would not otherwise exist. A healthy account usually blends all three, and the blended return is what actually matters for the business.

Once you know your total budget, the next question is how to split it. Two allocations matter: how you divide spend across the whole marketing mix, and how you divide the paid portion across platforms. Both should shift as you grow.

A common starting framework across the marketing mix by revenue stage:

The pattern to notice is that as a store grows, spend shifts away from pure acquisition and toward retention. Early on you need paid media to build a customer base. Later, with that base in place, email and retention deliver a higher return, and over-spending on acquisition produces diminishing results.

Within the paid budget itself, a sensible default is to put 35% to 45% into Google, 25% to 35% into Meta, and distribute the remainder across TikTok and other channels based on performance. Then let the data move the money. Lead with Google to capture existing demand efficiently, use Meta as your primary scale lever, and add TikTok where your product and audience suit it. Reallocate monthly toward whatever is beating your target return.

Attribution is the hardest part of modern paid media, and the part most stores get wrong. Privacy changes, cookie restrictions, and the simple fact that customers move across devices and channels mean the numbers inside each ad platform no longer tell the whole truth. Meta and TikTok both claim credit for the same sale, and the totals never reconcile with what your bank account shows.

The practical answer is to stop treating any single platform’s reported ROAS as gospel and instead watch the relationship between total ad spend and total revenue. Blended ROAS, your overall revenue divided by your overall ad spend, is harder for the platforms to inflate and far closer to the truth. Many sophisticated advertisers now use the marketing efficiency ratio, total revenue divided by total marketing spend, as their north star metric.

To measure honestly:

• Track blended ROAS and MER alongside platform numbers, and trust the blended figures when they disagree.
• Implement server-side tracking through each platform’s conversions API to recover signal lost to browser restrictions.
• Use a post-purchase survey asking customers how they heard about you, which captures the discovery channels attribution misses.
• Run holdout tests by pausing a channel and watching what happens to total revenue, the cleanest read on true incremental value.

This is the section most paid media guides skip, and the one that decides whether your spend is profitable. Paid media buys attention. What you do with that attention determines the return. Treating paid as a standalone channel, judged only on its own ROAS, is the single most common reason stores conclude that advertising does not work for them.

Two systems multiply the value of every pound you spend on ads. The first is conversion rate optimisation. If your landing pages and checkout convert at 3% rather than 2%, every campaign instantly returns 50% more without spending a penny extra on media. CRO is the cheapest way to improve ROAS, because it works on traffic you have already paid for.

The second is email marketing and retention. Most people who click your ad will not buy on the first visit. If you capture their email and nurture them, you convert a slice of that lost traffic at almost no extra cost, and you turn one-time buyers into repeat customers. Because retention raises customer lifetime value, it directly increases how much you can afford to spend to acquire each customer, which lets you outbid competitors who only measure the first sale.

Put together, these form a flywheel. Paid media drives new traffic, CRO converts more of it, email captures the rest and nurtures it, and retention lifts lifetime value so you can profitably spend more on paid media again. The stores that build this loop pull steadily ahead of those that judge each ad campaign in isolation. If you want help joining these pieces into one plan, our eCommerce growth team does exactly that.

• Most stores spend 7% to 12% of revenue on marketing, with paid media around 3% of revenue, scaling higher for fast growth.
• Set budgets from your unit economics and target cost per acquisition, not a generic percentage of revenue.
• Google Shopping captures demand at high returns (~5x), Meta scales prospecting (~1.9x), TikTok drives discovery (~1.4x).
• Lead the paid split with Google, scale with Meta, add TikTok where product and audience fit, and reallocate by performance.
• Trust blended ROAS and marketing efficiency ratio over any single platform’s self-reported numbers.
• Paid media only pays off as part of a flywheel with CRO, email and retention raising the value of every click.

Common questions about eCommerce paid media. Get in touch if yours is not here.