Paid
Organic
Ecommerce marketing agency · Omnichannel growth
Castle is an ecommerce marketing agency for online retailers. Paid search, paid social, email and SMS, SEO and AI search, CRO, Shopify, marketplaces and creative, run by one team and measured on the revenue your store makes, not on each channel’s own report.
Why joined-up matters
A typical order touches an ad, a search, a product page, an email and a review before it happens. When each of those sits with a different supplier, nobody owns the sale, and the budget goes to whoever reports it loudest.
Google, Meta and your email platform will each count the same purchase. Managed separately, that double counting looks like growth while total revenue stays flat.
Baymard’s average across 50 studies is that 70.22% of baskets are abandoned. Fixing the site, checkout and basket flows lifts the return on every channel at once.
Shoppers now find products in search, social feeds, marketplaces and AI assistants. Your products, feeds and content need to be right in all of them, and consistent.
What’s included
Pick the channels you need now and add the rest when the numbers support it. Whatever the mix, one growth lead owns the plan and reports on what it does for the whole store.
Google and Microsoft Ads built around your feed and your margins.
Measured on ROAS by product group
Meta, TikTok and Pinterest campaigns that create demand, not just retarget it.
Measured on new-customer revenue
Flows and campaigns that turn first orders into repeat customers.
Measured on repeat-purchase rate
Category and product pages that rank in Google and get cited by AI assistants.
Measured on non-brand organic revenue
Convert more of the traffic you already pay for.
Measured on conversion rate and AOV
A Shopify Partner team that builds, migrates and improves your store.
Measured on revenue per session
Sell where buyers already search, without undercutting your own store.
Measured on marketplace profit after fees
Ads, emails and product content made by our own designers and video team.
Measured on ROAS by creative
Every engagement includes
Case studies
Three online retailers, three different problems, one joined-up team. Every figure links back to the full case study.
A heritage appliance brand that set a target of 50% more online revenue in a year. We improved the existing site, built a new UX-focused one, launched Google and Facebook ads for the first time and grew Instagram from 8,000 to over 102,000.
A garden-supplies store with declining sales. We fixed the conversion basics on the Shopify store, then ran seasonal Google and Meta campaigns so more of the traffic it already had turned into orders.
A designer-inspired fragrance brand that wanted profitable growth. Tighter Google campaigns and Facebook video built on street blind tests meant spending less and selling more.
Results by store
Headline results from Castle’s published ecommerce case studies, with the period each one covers. Most were published in July 2024 and use the relative periods stated at the time.
| Store | What Castle ran | Sales | Conversion rate | Also |
|---|---|---|---|---|
| SwanSee case study | New site, CRO, Google, Meta, social, affiliate | +250%online revenue, year one | 1.7% → 2.1%year one | AOV +48%year one, against a 50% revenue target |
| Home and Garden ExtrasSee case study | Shopify CRO, Google, Meta | +119%last 90 days | +44%last 90 days | Orders +126%sessions +36% |
| GeepasSee case study | Shopify rebuild, Google, Meta | +126%last 7 days | +57%last 7 days | 7.02:1 blended ROASreturning customers +62% year to date |
| Nicholas Charles FragrancesSee case study | Google, Meta, video | +72%last 30 days, year on year | +239%same period | 6.13:1 Google Ads ROASaverage since the work began |
| Fizzy WhizSee case study | Shopify migration, Meta, Google, email | +82%month on month | +24%past month | Email sales +269.55%May vs previous month; Meta ROAS 10.41:1 |
Client reviews
…the results have been outstanding. They’ve completely turned around our online performance — Google Ads are running more efficiently than ever, Meta campaigns are consistently profitable, and our Shopify sales have seen real, measurable growth month after month.
…Smashing targets & 24/7 support which is a big bonus for us can’t thank them enough. Connor who’s trying different strategies & believe me they bring in the results!
I honestly can't say how good everyone is at Castle, they can't do enough for you and the work and numbers they produce out of this world. If I could leave 10 stars I would
The whole team at Castle International are an absolute asset to any business that needs a positive boost in their marketing strategy. Expertise, knowledge, patience and a friendly helpful attitude, aiming to give you a bespoke service throughout.
Our business has benefited massively by Castle and their team of creative experts. It is a wonderful company that is always working to achieve the best for you. They have a wealth of knowledge and offer outstanding marketing solutions always ensuring they deliver on their promise
A really great team who fully engaged with our enterprise and brought us rapidly into a whole different level of positive and sustained engagement with our target audience. Very very pleased to be working with them. Brilliant communicators. They've made a huge difference.
On camera
Trusted by
The omnichannel customer journey
Customers rarely buy on their first visit or through one channel. We plan every stage of the journey together, give each channel a clear job and a measure, then judge the whole on the revenue it adds to your store.
Reach people who have never heard of you, wherever they browse and search.
Measured onNew-customer revenue and cost per acquisition
Stay in front of them while they compare, with answers and proof.
Measured onAdd-to-basket rate and assisted conversions
Remove every reason to leave between basket and payment.
Measured onConversion rate and average order value
Turn a first order into a second, third and fourth.
Measured onRepeat-purchase rate and customer lifetime value
Make happy customers easy to hear, and easy to find.
Measured onReview volume, referral revenue and branded search
Where you are now
The first ninety days look very different for a new store and a ten-year-old one. Choose the stage that sounds most like yours to see what we would do first.
The first ninety days decide how quickly paid media can scale. We get measurement, the product feed and the basics of the store right first, so every pound spent after that teaches you something.
Scaling is where most stores lose margin, because every platform keeps claiming the same customers. We set ROAS targets by product margin, add channels one at a time and judge each on the new revenue it adds to the whole store.
When revenue stalls, more budget is rarely the answer. The cause is usually a mix of wasted spend, a conversion rate that has drifted, flows that were never finished and channels taking credit for each other.
A migration is the riskiest month in a store’s year: redirects missed, tracking broken, feeds disconnected, flows pointing at old URLs. Our Shopify developers and marketers plan it together, so revenue carries straight over.
The evidence
Online is close to three in every ten pounds of British retail, but most baskets are still abandoned and discovery is moving into AI assistants. The stores that grow work on every stage at once.
of all retail spending in Great Britain was online in August 2026. Online sales were 8.9% higher than a year earlier.
ONS · Sep 2026 · UKof shoppers who add to basket leave without buying: the average of 50 studies.
Baymard Institute · 2025 · Globalrise in a year in traffic to UK retail sites referred by generative AI tools such as ChatGPT.
Adobe Analytics · H1 2025 · UKmore orders reaching Shopify stores from AI search since January 2025, from a small base.
Shopify · Feb 2026 · GlobalShare of email sends vs share of email revenue
Klaviyo also finds flows earn nearly 18 times the revenue per recipient of one-off campaigns. That is why welcome, basket, post-purchase and replenishment flows go live before we scale paid traffic.
Sources: ONS, Retail sales, Great Britain: August 2026 (18 Sep 2026); Baymard Institute, Cart abandonment rate statistics (updated 22 Sep 2025); Adobe Analytics H1 2025 Online Spending Report, via IT Brief UK (24 Jul 2025); Shopify Q4 2025 earnings call (11 Feb 2026); Klaviyo Email Benchmarks 2026; Omnisend 2026 Ecommerce Marketing Report (29 Jan 2026, 2025 data); Harvard Business Review, Sopadjieva, Dholakia & Benjamin (Jan 2017); Omnisend omnichannel statistics (2021 data).
Growth levers
Ecommerce revenue is sessions × conversion rate × average order value, plus what customers spend when they come back. Set your numbers, switch on realistic improvements and watch them multiply rather than add.
Extra revenue a year
Where the extra comes from
Indicative only. Annual revenue = monthly sessions × conversion rate × average order value × 12, plus repeat revenue, where the repeat rate is the share of customers who place one more order in the year at the same order value. Uplifts are scenarios you choose, not forecasts. “Compounding” is the revenue the levers create together over and above their separate effects. Your free growth audit replaces these assumptions with your own data.
Why Castle
Ecommerce marketing rarely fails for lack of effort. It fails because the ads, the store, the emails and the reporting sit with different people who each optimise their own number.
| Feature | Castle | Separate channel agencies | In-house generalist |
|---|---|---|---|
| One lead accountable for total store revenue | Yes | No | Sometimes |
| Blended reporting across every channel | Yes | No | Sometimes |
| Paid search, social, email, SEO and CRO in one team | Yes | No | No |
| Shopify developers on the same team | Yes | Another agency | No |
| In-house design and video for ads and email | Yes | Extra cost | No |
| Budget moved between channels on evidence | Yes | No | Sometimes |
| You own every account and all the data | Yes | Not always | Yes |
| Contract terms | 30-day rolling | Often 6–12 months each | Salaries + tools |
Comparison reflects how Castle works and common market practice; it is not a review of any named provider.
The team
Castle’s paid media, email, SEO, CRO, creative and Shopify teams work together in our Liverpool studio at 17 Mann Island. One growth lead owns your numbers and brings in the specialists as the plan needs them.
Further reading
Ecommerce marketing in 2026, why traffic alone no longer convertsA realistic look at ecommerce marketing in 2026, why traffic alone no longer converts, and how UK ecommerce brands can grow sustainably.Read article
The future of eCommerce marketing in 2025 and beyondECommerce has evolved faster in the past five years than in the two decades before. With online competition at an all-time high, success now depends on more…Read article
The ROI of eCommerce SEO and paid advertising working togetherSEO builds long-term visibility, paid ads drive instant results – but together, they create unstoppable growth. At Castle, we combine SEO and paid…Read article
PPC for ecommerce: the ultimate guidePay-per-click PPC advertising can be very beneficial for promoting eCommerce stores. It has proven results for maximising leads and increasing revenue…Read article
Ecommerce is Changing Fast, and 2024 Proved ItA smart breakdown of the major ecommerce shifts seen in 2024, from changing customer behaviour and AI driven search to declining loyalty, faster checkouts…Read article
How data-led decision making transforms your marketing ROICreativity may win attention, but data delivers results. At Castle, we combine creative strategy with performance data to maximise ROI, refine campaigns in…Read articleRelated services
One Liverpool team runs every channel, so adding a service means one plan and one report, not another agency.
Buy the intentGoogle AdsSearch, Shopping, Performance Max and YouTube, managed on cost per sale.Explore the service→
Create the demandMeta AdsFacebook and Instagram ads with creative made in-house and tested properly.Explore the service→
Stores built to sellShopify DevelopmentShopify and Shopify Plus stores designed, built, migrated and optimised.Explore the service→
Outrank your competitorsSEOTechnical SEO, content and links that compound into enquiries.Explore the service→Questions
It grows an online store’s revenue across every channel that sells: paid search and Shopping, paid social, email and SMS, SEO and AI search, marketplaces, and the store itself through conversion rate optimisation. Castle runs these as one plan with one growth lead, so each channel has a clear job and the results are judged on what they add to total revenue.
It depends on your margins, order value and stage. Most stores start with Google Shopping and brand search to capture existing demand, Meta to create new demand, and email flows to keep customers. TikTok, Microsoft Ads, Amazon and AI search follow when tracking and creative can support them. Your free audit sets the order.
It depends on how many channels you need and how large the accounts are, so we scope each engagement rather than quoting one price for everyone. Ad spend is separate and paid directly to the platforms. Book a free growth audit and we will tell you what we would do and what it would cost.
No. We are a Shopify Partner and much of our ecommerce work is on Shopify and Shopify Plus, but we also work with WooCommerce stores and help retailers migrate between platforms. The marketing channels work the same whatever the store is built on.
Fixes to tracking, feeds, the checkout and email flows often show within weeks, because they improve traffic you already have. Paid channels usually need six to twelve weeks to gather data and settle, and SEO compounds over months. We set expectations by channel in the audit.
On blended numbers first: total revenue against total marketing spend, split into new and returning customers. Each channel also has its own measure, such as ROAS by product group or repeat-purchase rate. We use GA4, platform data and attribution tools such as Triple Whale, and check tracked revenue against actual sales.
Yes. We work across Amazon Seller Central and Vendor Central, covering listings, A+ content and Sponsored ads, and we plan marketplace pricing alongside your own store so the two channels do not undercut each other.
Shoppers increasingly ask AI assistants for product recommendations, and traffic from them to UK retail sites is growing fast from a small base. Clean product feeds, structured data, detailed product content and a strong reputation in reviews all help your products appear. We build that into SEO and feed work rather than treating it as a separate channel.
Yes. Some clients hand us everything; others keep email or social in-house and use us for paid media, SEO or Shopify. We agree who owns what at the start and report on the same blended numbers, so nothing falls between teams.
No. We work on 30-day rolling contracts. You own your ad accounts, email platform and data throughout, and if something is not working we would rather tell you plainly than keep invoicing.
Free ecommerce growth audit
If your store has stopped growing, we will go through your ads, analytics, email and site and tell you where the next 20% is, before any talk of a retainer.
