Short version: An ecommerce PPC agency runs your paid search and shopping channels, usually Google Ads and Microsoft Ads, and the good ones spend most of their time on three things nobody advertises in a pitch deck: your product feed, your conversion tracking, and campaign structure that separates products by margin instead of blending them. Pricing comes in three shapes, flat retainer, percentage of ad spend, or a hybrid, and each one distorts incentives differently. This guide covers what the work actually involves, what the fees really buy at each budget level, and the specific questions that separate an agency who will grow your store from one who will report on clicks for a year.
PPC and Google Ads get used interchangeably, and for most ecommerce brands the distinction barely matters in practice: paid search is where the money goes, Google is where most of the paid search is, and Shopping and Performance Max carry the products. What does matter is that ecommerce PPC is a different discipline from lead generation PPC. A lead gen account optimizes toward form fills and phone calls; an ecommerce account optimizes toward revenue against margin, through a product feed, across a catalog where some SKUs make money and others quietly lose it. Agencies that are excellent at one are frequently mediocre at the other, and the pitch rarely tells you which you are talking to.
What an ecommerce PPC agency actually manages
The channel list is short: Google Search, Google Shopping and Performance Max, Google remarketing, and usually Microsoft Ads as a smaller parallel account. Some agencies bundle paid social; many, including specialists, deliberately do not, because feed-driven search work and creative-driven social work reward completely different skills.
Underneath those channels, the work that decides results is unglamorous:
The product feed
In Shopping and Performance Max, your feed is your keyword list. Google reads product titles, descriptions, and attributes to decide which searches your products can appear for, so a thin feed locks you out of auctions no bid can buy back. Serious agencies rewrite titles, build supplemental feeds, and use custom labels to segment products by margin and price tier. Agencies that never mention the feed are managing bids on a foundation they have not inspected.
Conversion tracking
A surprising number of ecommerce accounts report more revenue than the store actually took, usually from duplicate purchase events or add-to-cart values counted as sales. Smart Bidding then optimizes confidently toward inflated numbers. Reconciling Google Ads conversion values against real orders is often the highest-return single fix in an account, and it should happen before any scaling conversation.
Campaign structure
Brand traffic separated from non-brand so Performance Max stops taking credit for sales you would have won for free. Products grouped so a 60% margin hero is not bid identically to a clearance item. Structure is what makes an account legible; without it, nobody can say which products actually make money.
The weekly work
Search term reviews and negative keywords, budget moved toward what is profitably scaling, bid strategy adjustments, feed fixes, and Merchant Center disapprovals cleared before they quietly delist your bestsellers. This is the part that compounds, and the part that gets skipped when an account is priced too cheaply to justify the hours.
The three pricing models, and what each one rewards
Flat monthly retainer
A fixed fee regardless of spend. Predictable for you, and it removes any incentive to inflate budgets. The risk is the opposite: once the fee is fixed, a busy agency has no financial reason to chase your next growth increment. Works best when the scope is explicit about what happens each week.
Percentage of ad spend
Typically 10-20% of monthly spend, sometimes lower at large budgets. It scales naturally with account size, which feels fair, but it pays the agency more for spending more, which is precisely the wrong incentive on a channel where the right answer is sometimes to spend less on unprofitable products. If you use this model, tie reviews to profitability rather than volume.
Hybrid: base fee plus percentage
A floor that funds the baseline work plus a variable component that participates in growth. This is the most common structure at the specialist end because it survives both quiet months and scaling months without either side resenting the arrangement.
A fourth model, pure performance or revenue share, sounds appealing and rarely works in ecommerce. Attribution is contested, the agency does not control your pricing, stock, or site, and any agency willing to be paid purely on revenue will naturally push volume over margin. Treat it as a warning sign rather than a bargain.
What the fees actually buy
Roughly, and with wide regional variation: small accounts spending a few thousand a month typically pay a few hundred to around a thousand for management; mid-size accounts pay in the low thousands; large accounts negotiate hybrid arrangements. The number matters less than what it funds.
A fee that is too low is not a bargain, it is a scope reduction you did not agree to. Under a certain price nobody can afford to do search term reviews, feed work, and tracking hygiene on your account, so those disappear first and the account still runs, just leaking. The waste in a neglected account, commonly 20-30% of spend, routinely exceeds the fee difference between a cheap provider and a competent one. On a £10,000 monthly budget, a leak of that size costs more per month than most management fees.
The useful way to frame it: management fee plus wasted spend is your real cost of the channel. Judge that total, not the invoice.
How to judge an ecommerce PPC agency before you sign
Most evaluation advice tells you to check certifications and reviews. Both are close to worthless as signals, since the badge requires an exam and the reviews are curated. These are more discriminating:
Ask who works on the account day to day. Pitches are given by senior people; accounts are often run by juniors. Ask for the name, their experience, and how many accounts they carry. An answer above roughly twenty accounts per person means yours gets minutes a week, not hours.
Ask what they would do about your product feed. A specialist will already have opened your Shopping results and will have opinions on your titles. Someone who treats the feed as a technical detail for your developers is telling you where their attention will not go.
Ask how they would verify your conversion tracking. The right answer involves reconciling Google Ads reported revenue against actual store orders, not "we will check the tag is firing".
Ask what they would want to change in the first thirty days. Strong answers are specific and structural: brand exclusions, campaign segmentation, feed titles, tracking. Weak answers are generic: optimize bids, test ad copy, add negatives.
Ask what happens if you leave. The account, the data, and the tracking must be yours and stay yours. Agencies that run campaigns inside their own manager account and take the history with them are holding your growth hostage by design.
Red flags worth walking away from
Guaranteed ROAS. Nobody can promise a return on a channel where competitors, seasonality, and your own stock levels move the outcome. A specific guaranteed number is a sales technique, not a forecast.
Reporting built on impressions, clicks, and CTR. If the monthly report leads with traffic metrics rather than revenue against target ROAS, the agency is measuring its own activity rather than your outcome.
No questions about your margins. An agency that never asks what you keep on an order cannot set a meaningful ROAS target, because break-even is a function of margin and nothing else. This single question separates operators from account babysitters.
Long lock-in contracts. Ninety days is fair while an account stabilizes. Twelve months with no exit usually protects the agency from the consequences of its own performance.
Agency, freelancer, or in-house
A specialist freelancer or boutique gives you senior attention directly, which is usually the best value below serious spend levels, with the tradeoff of key-person risk. A larger agency offers redundancy and broader services, with the tradeoff that your account may be run by whoever is most junior on the team. In-house makes sense once spend is large enough that a full-time salary is cheaper than fees, though hiring PPC talent well is its own difficult problem, and a single in-house person has nobody to check their blind spots.
The honest summary: at most ecommerce budgets, the deciding factor is not agency versus freelancer versus in-house, it is whether the person actually in the account is experienced with product feeds and has enough time to do the weekly work. Every structure can deliver that, and every structure can fail to.
What good looks like in the first ninety days
Weeks one to two are diagnosis and repair, not scaling: tracking verified against real orders, Merchant Center cleaned, brand separated from non-brand, obvious waste removed. Weeks three to six are restructure and stabilization, where the account gets a shape that matches your catalog and margins, and performance often dips briefly while bidding relearns. Weeks seven to twelve are where results should become visible and the conversation shifts to scaling what is profitable.
An agency that starts by raising budgets in week one, before verifying whether the conversion data is even accurate, is scaling on numbers nobody has checked.
Frequently asked questions
What does an ecommerce PPC agency do?
It manages your paid search and shopping channels, in practice Google Ads and often Microsoft Ads. Day to day that means product feed optimization, conversion tracking accuracy, campaign structure that separates brand from non-brand and segments products by margin, plus weekly search term reviews, budget allocation, and bid strategy management against a ROAS target derived from your margins.
How much does an ecommerce PPC agency cost?
Fees are structured as a flat retainer, a percentage of ad spend, usually 10-20%, or a hybrid of both, and vary widely by market and account size. The more useful number is management fee plus wasted spend combined, because a cheap fee that omits feed work and search term reviews typically leaks more budget than it saves.
Is PPC the same as Google Ads?
PPC, pay per click, is the broader category covering paid search across platforms, while Google Ads is the largest platform within it. For most ecommerce brands the majority of PPC budget sits in Google, with Microsoft Ads as a smaller parallel channel, so the terms get used interchangeably even though PPC is technically the wider term.
How do I know if my PPC agency is doing a good job?
Look for three things: revenue against a ROAS target set from your actual margins rather than a generic benchmark, structural changes in the account over time rather than only bid adjustments, and reporting that leads with profitability rather than clicks and impressions. If nobody has ever asked what you keep on an order, the target they are optimizing toward is arbitrary.
Bringing it together
Choosing an ecommerce PPC agency comes down to whether the person actually working in your account understands product feeds, verifies conversion data before scaling, and structures campaigns around your margins. Everything else, certifications, office size, the pitch deck, is decoration. Work out your break-even ROAS with our ROAS calculator before any agency conversation so you can judge their targets, read our guide to hiring a Google Ads agency for ecommerce for the interview process, and if you want a second opinion on your current account, book a free 30-minute audit call and you will leave with your three biggest fixes whether or not we ever work together.
About the author
This guide is written by Vasant Chaudhary, a Google Ads specialist with more than five years of experience managing over 50 ecommerce and lead generation accounts across the US, UK, and India. He focuses on product feeds, conversion tracking, and campaign structure, the levers that decide whether a PPC budget produces profit or just traffic. Get in touch or start with a free audit call.
