A PPC agency charges 15–20% of ad spend or a fixed management fee (typically £600–£3,000/month) to manage your Google Ads, Meta Ads, and other paid media campaigns professionally. An in-house PPC hire costs £35,000–£55,000/year (£2,900–£4,600/month) in salary plus tools, training, and management time. For UK businesses spending less than £20,000/month on ads, a good PPC agency typically delivers better ROAS than a single in-house hire because agencies provide access to senior specialists, proprietary tooling, and cross-account learnings that individual in-house hires cannot match.
PPC is unique among digital marketing channels in that poor management is immediately and measurably costly — wasted ad spend is direct profit loss. The quality of PPC management matters enormously, which makes the choice of agency vs. in-house consequential in ways that some other marketing decisions are not.
When a PPC agency makes more sense
- Ad spend under £20,000/month — the agency management fee buys more expertise than you could hire in-house at that spend level
- Multiple platforms — managing Google Ads, Meta Ads, LinkedIn, and TikTok simultaneously requires broad expertise that is rarely found in one in-house hire
- Testing and benchmarking — agencies with multiple clients in your sector can apply cross-account learnings to your campaigns
- Speed of capability — an experienced agency can launch and optimise a profitable campaign within weeks; an in-house hire takes months to learn your business and build campaign history
When in-house PPC is the better choice
- Ad spend above £50,000/month — at this scale, management fees for an agency may exceed in-house salary costs while an in-house hire provides more dedicated focus
- Complex product catalogues — eCommerce businesses with thousands of SKUs benefit from in-house PPC who deeply understands the product range and can optimise at a granular level
- Rapid iteration needs — businesses where daily budget decisions must integrate with sales, inventory, and commercial goals benefit from in-house agility
- Multiple brands or accounts — managing several brands internally can be more efficient with a dedicated team than coordinating multiple agency relationships
Industry standard is 10–20% of ad spend for ongoing PPC management, with minimum monthly fees typically ranging from £500 to £1,500. For low ad spend accounts (under £3,000/month), a flat management fee of £600–£1,200/month is more appropriate than a percentage (which would be too low to sustain quality management). For high ad spend accounts (above £30,000/month), a percentage fee of 8–12% with a cap is standard — without a cap, percentage fees can become disproportionate relative to the management work required.
Key PPC performance indicators: ROAS (revenue ÷ ad spend; typically should be 3×+ for eCommerce, but depends on margins), cost per lead (compare against revenue per customer and lead-to-close rate), Quality Scores (7–10 is good; below 5 indicates poor ad-to-landing-page alignment), impression share (are you winning the auctions for your best keywords?), and wasted spend percentage (what proportion of spend is on irrelevant searches, identifiable via Search Term reports). If you cannot answer these questions about your current campaigns, your campaigns are almost certainly under-managed.