A digital marketing agency runs paid acquisition (PPC, paid social), organic acquisition (SEO, content, social), retention (email, lifecycle, loyalty), and analytics tied to revenue. Some also do brand, web design, video, and PR. They don't (typically) do product development, sales execution, or customer support. Pricing £500/mo (boutique) to £50k/mo (full-service multi-channel). Most SMEs need 2–3 channels, not all 12.
Paid acquisition: Google Ads, Meta, LinkedIn, TikTok, Microsoft. Channel selection depends on buyer behaviour.
Organic acquisition: SEO (technical, content, links), organic social, content marketing, partnerships.
Retention: email + SMS via Klaviyo / HubSpot / Customer.io, loyalty programmes, win-back campaigns.
Analytics: GA4 setup, attribution modelling, dashboards, weekly / monthly reporting tied to business KPIs.
Creative production: ad creative, landing pages, email design, sometimes video. Bigger agencies bundle; specialist agencies pull in production partners.
Product development. Sales calls / demos / closing. Customer support. Operations. Finance. Legal. Compliance sign-off (your team owns).
Agencies augment marketing capacity. They don't replace your sales team or your product team. The most common failure mode is hiring an agency expecting product-fit problems to solve themselves — agencies amplify; they don't fix broken products.
Freelancer / boutique (£500–£2,000/mo): single channel, single specialist. Small agency (£2,000–£6,000/mo): 2–3 channels, dedicated AM. Mid-tier (£6,000–£15,000/mo): full multi-channel, dedicated team. Enterprise (£15,000–£50,000/mo): dedicated team, attribution, exec reviews, creative production.
Plus media spend: minimum £1,500/mo per paid channel for statistical signal within 60 days.
Specialist agencies (PPC-only, SEO-only, email-only) win on depth and channel-specific expertise. Trade-off: you manage multiple agencies, cross-channel coordination is on you.
Full-service agencies win on coordination and one-throat-to-choke. Trade-off: depth in any one channel may be shallower than a specialist's.
For SMEs below £2m revenue, full-service is usually right. Above that, mix of specialists with strong in-house coordination wins.
"Most successful SaaS companies above £5m ARR run 2–3 specialist agencies (one PPC, one SEO, one content) coordinated by an in-house growth lead, rather than one full-service agency."
Three KPIs that matter at agency-tier: (1) qualified pipeline / lead volume tied to attributed channels, (2) cost per acquisition or cost per qualified lead within target band, (3) revenue trajectory year-over-year compared to industry benchmark.
Vanity metrics that don't matter: impressions (without CTR context), traffic (without conversion context), follower count (without engagement context), email open rate (without click context).