Every ecommerce marketing agency lists an impressive range of services on its website. Paid media, SEO, email marketing, CRO, creative strategy, analytics, influencer marketing, content production: the service pages look comprehensive. The reality is often different. Many agencies list services they can technically deliver but don’t deliver well, staffing secondary capabilities with junior generalists while concentrating their senior talent on one or two core strengths. For ecommerce brands trying to decide between a single full-service partner and a roster of specialists, the question isn’t which model is better in theory; it’s how to evaluate what you’re actually getting versus what’s being sold.
This matters more than ever because budgets are under pressure. The Gartner 2025 CMO Spend Survey found that 39% of CMOs are planning reductions to their agency allocations, with the top actions being cutting underperforming agency relationships and renegotiating contracts. Agency spend has dropped to 20.7% of total marketing budgets, the lowest share in years. When every pound of agency spend faces scrutiny, understanding exactly what services you need, and whether your agency genuinely delivers on each one, becomes a commercial imperative rather than an academic exercise.
The Core Services an Ecommerce Agency Should Deliver
Not every ecommerce brand needs every service, but there’s a baseline set of capabilities that any agency positioning itself as a serious ecommerce partner should be able to execute at a high level. These fall into three categories: acquisition, conversion, and retention.
On the acquisition side, paid media management is the most common starting point. For ecommerce, this means Meta advertising (including Advantage+ Shopping campaigns and dynamic product ads), Google Ads (Search, Shopping, Performance Max), and increasingly TikTok. The quality indicator here isn’t whether the agency can run campaigns on these platforms; virtually any agency can. It’s whether they understand ecommerce-specific mechanics: product feed optimisation, catalogue-based creative, dynamic remarketing structures, and measurement frameworks that account for cross-platform attribution. An agency that manages your Google Shopping feed with the same rigour as your search campaigns is operating at a different level from one that treats Shopping as an afterthought.
Creative strategy sits alongside paid media as an acquisition function, not a production function. For ecommerce, this means the agency can develop creative concepts informed by performance data, produce assets at the volume required to prevent creative fatigue (which for brands spending above £30,000 per month on paid social typically means 15 to 25 new assets monthly), and iterate based on testing results. An agency that outsources all creative production to freelancers with no feedback loop to the media team isn’t delivering creative strategy; it’s delivering a production service.
SEO for ecommerce is structurally different from SEO for content businesses or lead generation sites. It involves technical considerations (site architecture for large product catalogues, pagination handling, faceted navigation, structured data for products), content strategy (category page optimisation, buying guide content, topical authority building), and ongoing maintenance (managing out-of-stock products, seasonal pages, URL structures during site migrations). An agency listing SEO as a service but staffing it with one generalist who handles both your ecommerce site and a solicitor’s blog isn’t equipped for the complexity of ecommerce search.
Conversion and Retention: Where Most Agencies Fall Short
The acquisition services are what most agencies lead with, because they’re the most visible and the easiest to sell. Conversion and retention services are where the gaps typically emerge.
Conversion rate optimisation requires a different skill set from paid media management. It demands UX research capability (heatmaps, session recordings, user testing), statistical literacy (understanding test validity, sample size requirements, confidence intervals), and front-end development access to implement changes. Many agencies list CRO as a service but deliver it as occasional landing page tweaks rather than a structured testing programme. The tell is simple: ask the agency how many tests they ran for their last three ecommerce clients in the past quarter, what their win rate was, and how they calculate statistical significance. If the answers are vague, the CRO capability is thin.
Email and SMS marketing has become a critical retention function for ecommerce, yet many agencies treat it as an add-on rather than a core service. A genuine email capability means the agency can build and manage automated flows (welcome series, abandoned cart, post-purchase, win-back, replenishment), segment audiences based on purchase behaviour and engagement, maintain deliverability, and connect email strategy to the broader acquisition and retention model. An agency that sends your weekly newsletter and runs the occasional promotional campaign isn’t providing email marketing services in any meaningful sense.
Analytics and reporting is perhaps the most consistently oversold service in the agency world. Every agency promises “transparent reporting” and “data-driven decision making.” The reality is that most agency reporting consists of platform-exported dashboards showing channel-specific metrics (ROAS, CPA, click-through rates) with little connection to actual business outcomes. Genuine analytics capability means the agency can reconcile platform-reported data with your backend revenue, build blended measurement frameworks (MER, contribution margin analysis), and provide insights that inform commercial decisions rather than just describing what happened in the ad platforms last month.
One Agency vs Multiple Specialists: A Decision Framework
The one-agency-versus-specialists debate doesn’t have a universal answer, but the decision framework is clearer than most brands realise. It comes down to three factors: your revenue stage, your internal capability, and the complexity of your channel mix.
For brands between £1M and £5M in revenue, a single agency handling paid media and creative, with email either managed in-house or by a specialist, is typically the most efficient model. At this stage, the volume of work across channels doesn’t justify multiple agency relationships, and the coordination overhead of managing three or four partners would consume more of your time than any specialisation benefit would return. The key is finding an agency whose core strength aligns with your primary growth lever, which for most brands at this stage is paid media.
Between £5M and £15M, the calculus shifts. Your channel mix is more complex, the stakes of each channel are higher, and the depth of expertise required in each area exceeds what a single agency can typically provide without compromising quality somewhere. This is the revenue range where many brands move to a primary agency handling paid media and creative, with specialists for email/retention and potentially SEO or CRO. The coordination burden increases, but so does the quality of execution across channels. The critical requirement is that someone, whether your internal team or a lead agency, owns the overall strategy and ensures channels work together rather than operating in silos.
Above £15M, most brands need either a genuinely full-service agency with deep expertise across all functions (these exist but are rare) or a structured roster of specialists with a clear lead-agency model. The risk at this stage isn’t the cost of multiple agencies; it’s the fragmentation of strategy and data. An ecommerce marketing agency serving as the strategic lead, with specialists supplementing specific functions, often produces the best results because it maintains strategic coherence while accessing best-in-class execution.
Red Flags in Service Offerings
Certain patterns in how agencies present their services should prompt closer examination. An agency that lists 15 or more distinct services but has fewer than 30 staff is almost certainly outsourcing significant portions of that work or staffing services thinly. That’s not inherently problematic, but you should know which services are delivered by senior in-house team members and which are handled by contractors or white-label partners.
Be cautious of agencies that position every service as equally strong. No agency is world-class at everything. The honest ones will tell you where their depth sits and where they provide competent but not exceptional execution. An agency that claims to be equally expert in Meta ads, Google Ads, SEO, email, CRO, influencer marketing, and content production is either very large or overstating its capabilities. Ask which services generate the most revenue for the agency and where their longest-tenured senior staff sit. That’s where the real expertise lives.
Watch for agencies that can’t articulate how their services connect. The value of a multi-service agency isn’t just the convenience of a single relationship; it’s the integration between functions. Creative strategy informed by media performance data, CRO insights feeding back into ad creative, email capture strategy connected to paid media ROI: these integration points are where multi-service agencies create value that specialists working in isolation can’t. If the agency describes each service in a silo without explaining the connections, the integration probably doesn’t exist in practice.
How to Audit Your Current Agency’s Service Delivery
If you’re already working with an agency and questioning whether you’re getting genuine delivery across all contracted services, a simple audit framework will reveal the truth quickly. For each service in your scope of work, ask three questions: who specifically works on this (name, role, seniority, and what percentage of their time is allocated to your account), what was the output in the last 90 days (specific deliverables, not vague descriptions), and what measurable impact did it have (tied to a business metric, not a platform metric)?
Services where the agency can answer all three questions with specifics are being genuinely delivered. Services where the answers are vague, where the person responsible is unclear, or where there are no tangible outputs from the last quarter are being under-delivered regardless of what’s in the contract.
This audit also reveals whether you’re paying for services you don’t need. Many ecommerce brands carry agency scopes that include services added during onboarding that never became relevant, or that made sense at a previous revenue stage but have since been outgrown. Trimming these and redirecting budget toward the services that actually drive results is one of the simplest ways to improve your agency ROI.
For brands that want clarity on which services will actually move the needle at their stage, Rozee Digital takes a scope-first approach, building service packages around what the business needs rather than selling a fixed menu. That’s the difference between an agency that lists services and one that delivers them.
