What Does a Digital Marketing Agency Actually Do?

A digital marketing agency plans, executes, and measures online marketing campaigns to grow your business — typically through SEO, paid advertising (Google Ads, Meta), social media, content marketing, email marketing, and web design. They replace or supplement an in-house marketing team.

Core services most agencies offer

• SEO: Making your website rank higher in Google for the keywords your customers search
• PPC / Paid Ads: Running Google Ads, Meta Ads, LinkedIn Ads to drive immediate traffic and leads
• Social Media: Managing your brand presence on Instagram, TikTok, LinkedIn, etc.
• Content Marketing: Creating blog posts, guides, videos that attract and educate potential customers
• Email Marketing: Email campaigns and automation to nurture leads and retain customers
• Web Design: Building or redesigning your website to convert visitors into customers

Agency vs freelancer vs in-house

Agency: Multi-disciplinary team, broader expertise, higher cost. Best for businesses that need multiple channels managed simultaneously.

Freelancer: Specialist in one area, lower cost, limited bandwidth. Best for businesses that need one specific skill (e.g., just SEO or just design).

In-house: Full-time team member, deep brand knowledge, highest total cost (salary + benefits + tools). Best for businesses spending £10k+/month on marketing with complex, ongoing needs.

When should you hire an agency?

1. You are spending more than £2,000/month on marketing and not seeing ROI
2. You need expertise across multiple channels (SEO + ads + social + email)
3. You do not have time to manage marketing alongside running your business
4. You need to scale marketing quickly without the overhead of hiring

What to expect in terms of cost

London digital marketing agency retainers typically run £2,500–£15,000/month. Meridian starts at £490/month for single-channel Starter packages, with full-service Growth packages from £1,490/month — 40% below the London market average.