Paid Search Agency: What You’re Actually Buying

A paid search agency manages your Google Ads, Bing Ads, and related search campaigns on your behalf, handling everything from keyword strategy and bid management to ad copy and conversion tracking. The right agency accelerates revenue. The wrong one burns budget while producing reports that look impressive and deliver nothing.

This article is for marketers and business owners who want to make a clear-eyed decision about whether to hire a paid search agency, what to expect from one, and how to tell the difference between an agency that knows what it’s doing and one that is very good at appearing to.

What Does a Paid Search Agency Actually Do?

At its core, a paid search agency manages campaigns on platforms where advertisers bid for placement when users search specific terms. Google Adwords, now rebranded as Google Ads, remains the dominant platform, though Microsoft Advertising commands a meaningful share of certain audiences, particularly older demographics and B2B buyers using corporate devices.

The agency’s job covers several distinct workstreams. Keyword research and selection. Campaign architecture. Ad copy writing and testing. Bid strategy, which can range from manual adjustments to automated bidding driven by Google’s machine learning. Landing page recommendations. Conversion tracking setup. And ongoing optimisation, which is where the real work either happens or doesn’t.

Good agencies also do something less visible but more valuable: they interpret what the data is telling you and translate it into commercial decisions. Not “your CTR improved by 12%”, but “this campaign is generating leads at £42 each and your sales team closes 1 in 5, so your cost per acquisition is £210 against a product margin of £800. We should scale.”

That kind of commercial fluency is rarer than it should be. I’ve sat in agency reviews where the entire deck was built around vanity metrics, and the client nodded along because they didn’t know what else to ask for. That’s a failure on both sides, but the agency carries more of the blame.

If you want broader context on how paid search fits into the wider performance marketing landscape, the Paid Advertising Master Hub covers the full picture, from search and social to programmatic and beyond.

How Fast Can Paid Search Actually Deliver?

Faster than almost any other channel. That’s the honest answer, and it’s the reason paid search became the backbone of digital acquisition budgets.

I saw this firsthand at lastminute.com. We launched a paid search campaign for a music festival, and within roughly 24 hours we had driven six figures of revenue. The campaign itself wasn’t complicated. The targeting was clean, the intent was obvious, the offer was right. Paid search didn’t need to be clever. It needed to be in front of the right person at the right moment, and it was.

That experience shaped how I think about paid search as a channel. It’s not magic. It’s demand capture. People are already looking for what you’re selling. Your job is to show up, make a compelling offer, and not get in your own way. Paid ads can outperform organic results precisely because they intercept buyers at the moment of intent, not just the moment of curiosity.

The flip side is equally important to understand. Paid search cannot create demand that doesn’t exist. If nobody is searching for your product category, bidding on keywords won’t fix that. I’ve seen brands burn significant budget trying to use paid search to educate a market that wasn’t ready to buy. That’s a content and awareness problem, not a search problem.

What Are the Different Types of Paid Search Agency?

Not all paid search agencies are built the same, and the differences matter more than most buyers realise when they’re first shopping for one.

Full-service digital agencies offer paid search as part of a broader suite that might include SEO, social, content, and creative. The advantage is integration. The risk is that paid search becomes a secondary service managed by a junior team while the agency’s attention goes elsewhere.

Specialist PPC agencies focus exclusively on paid media, often across search and social. They tend to have deeper technical expertise and more experienced practitioners working on your account. For businesses where paid search is a primary acquisition channel, a specialist is usually the better choice. Our breakdown of what to expect from a PPC agency covers the structure and pricing models in more detail.

Industry-specialist agencies focus on specific verticals, whether that’s ecommerce, legal, healthcare, or home services. If your category has specific compliance requirements or audience nuances, an agency that already knows the territory can save you significant time and wasted spend.

Freelance consultants sit outside the agency model entirely. For smaller budgets or businesses that need strategic input without full account management, a senior freelance specialist can be a cost-effective option. The risk is capacity and coverage, particularly if you need someone reactive during campaign issues.

There’s also a growing category of performance-only or commission-based models, where the agency takes a percentage of revenue rather than a flat fee. These can align incentives well, but they require strong tracking and clear attribution agreements before you start.

How Do Paid Search Agencies Charge?

Fee structures vary, and the model you agree to has a direct effect on where the agency’s incentives sit. This is worth understanding before you sign anything.

The most common model is a percentage of ad spend, typically somewhere between 10% and 20%. This is simple to administer, but it creates a structural misalignment: the agency earns more when you spend more, regardless of whether that additional spend is producing returns. It doesn’t mean the agency will behave badly, but it’s a dynamic worth being aware of.

A flat monthly retainer removes the spend-linked incentive. You pay a fixed management fee regardless of budget. This works well for businesses with stable, predictable ad spend. It can create the opposite problem, though: an agency that has little incentive to push for more budget even when scaling would be commercially sensible.

Performance-based models, where the agency earns a fee tied to leads, sales, or revenue, are gaining traction. They sound appealing but require careful definition. Attribution disagreements are common, and if your sales cycle is long or multi-touch, agreeing on what the agency actually caused is genuinely difficult.

For a detailed breakdown of what you should expect to pay across different account sizes and service levels, the article on Google advertising fees covers the numbers in practical terms.

What Should You Expect From a Paid Search Agency in the First 90 Days?

The first 90 days of any agency relationship tell you most of what you need to know about whether it’s going to work.

In the first two to four weeks, a competent agency should be auditing your existing account structure if one exists, completing keyword research, mapping your conversion tracking, and building campaign architecture. This is not the time for big spend. It’s the time for getting the foundations right.

I’ve seen agencies go live with campaigns in week one because the client was impatient. That impatience is understandable. But launching before your tracking is verified, your landing pages are optimised, and your negative keyword lists are built is how you waste the first month’s budget learning things you should have known before you started.

By weeks four to eight, you should have live campaigns with real data coming in. The agency should be actively testing ad copy variations, refining match types, and adjusting bids based on what’s converting. Quality Score optimisation matters here: improving the relevance between your keywords, ads, and landing pages directly reduces your cost per click and improves ad position.

By day 90, you should have a clear picture of which campaigns are performing, which need restructuring, and what the path to scale looks like. If the agency is still talking about “gathering data” at the three-month mark without any directional conclusions, that’s a problem.

One thing I’d always push for in the first 90 days: a session where the agency walks you through the account structure and explains their logic. Not a slide deck. The actual account. If they can’t explain clearly why they’ve structured things the way they have, that tells you something.

How Do You Evaluate Whether a Paid Search Agency Is Performing?

This is where a lot of client-agency relationships go wrong. The client doesn’t know what good looks like, so they accept whatever the agency reports as the measure of success.

The metrics that matter depend on your business model. For ecommerce, return on ad spend is the primary measure. For lead generation, cost per qualified lead and lead-to-close rate are what count. For brand campaigns, you’re measuring something softer, and you should be honest with yourself that attribution will be imperfect.

What you should be sceptical of: agencies that lead with impressions, reach, or click-through rate without connecting those numbers to revenue. Conversion rate is a more meaningful indicator than raw traffic volume, and a good agency will know that.

You should also be running your own benchmarks. What was your cost per acquisition before the agency? What is it now? What’s the trend over time? If you’re entirely dependent on the agency’s reporting to understand performance, you’ve handed over too much control.

For businesses running Google Ads specifically, understanding the fundamentals of PPC management services gives you the vocabulary to ask the right questions and recognise when the answers don’t add up.

What Makes a Good Client-Agency Brief for Paid Search?

Early in my career, before I was running agencies, I was on the agency side of a Guinness brainstorm. The founder had to leave for a meeting and handed me the whiteboard pen. My internal reaction was something close to panic. But the thing that saved the session wasn’t bravado. It was having enough information about the business problem to ask the right questions and keep the thinking grounded.

A good brief does the same thing for your paid search agency. It gives them enough context to ask the right questions and make decisions that serve the business, not just the account.

A brief that works should cover: what you’re selling and to whom, what the conversion event is and how you’re tracking it, what you’ve tried before and what happened, what your target cost per acquisition is and how you arrived at that number, what your seasonal patterns look like, and who your competitors are in the paid search auction.

What most briefs miss: the commercial context. An agency that understands your gross margin can make very different decisions about where to bid aggressively and where to pull back. One that doesn’t will optimise for cost per click without any sense of what a conversion is actually worth.

If you’re briefing an agency to run paid search alongside other channels, including platforms like TikTok Ads, make sure you’re clear about how you expect the channels to interact. Paid search and social serve different functions in the purchase funnel, and conflating them produces muddled strategy.

Are There Industries Where Paid Search Agencies Add Particular Value?

Paid search works best where purchase intent is clear, the product or service has an established search volume, and the economics support the cost of acquisition. That covers a very wide range of industries, but some sectors benefit disproportionately from agency expertise.

Legal and financial services operate in highly competitive, high-CPC auctions where account structure and Quality Score management make a material difference to cost efficiency. Getting this wrong is expensive very quickly.

Ecommerce benefits from agency expertise in Shopping campaigns, feed optimisation, and ROAS-based bidding strategies. The complexity scales with catalogue size, and managing a large product feed well is a genuine skill.

Local services, from home improvement to healthcare to hospitality, often see strong returns from paid search because local intent is high and competition, while growing, is still manageable in many markets. The article on Google Ads for beauty salons is a useful example of how paid search principles apply in a local service context.

B2B businesses with longer sales cycles can use paid search effectively for lead generation, but the attribution picture is more complex. A B2B buyer might click a paid ad, then spend three months reading content, attending a webinar, and talking to sales before converting. Crediting the original click with the full value of that conversion overstates what paid search delivered.

What Are the Most Common Mistakes Paid Search Agencies Make?

Having managed agencies and worked with them as a client, I’ve seen the same mistakes repeat with enough frequency to be worth naming directly.

Over-reliance on broad match keywords. Broad match has its place, but running broad match without strong negative keyword management is how you end up paying for irrelevant traffic. I’ve audited accounts where 30% of spend was going to searches that had nothing to do with the client’s product. The agency’s response was that broad match “helps the algorithm learn.” That’s true, up to a point. It’s not a reason to ignore search term reports.

Setting and forgetting automated bidding. Smart bidding strategies from Google can work well, but they require sufficient conversion data to function properly, and they need human oversight. An agency that hands everything to automation and stops actively managing the account is not earning its fee.

Ignoring landing page quality. Paid search agencies sometimes treat the landing page as someone else’s problem. It isn’t. The landing page is part of the campaign. A technically excellent campaign sending traffic to a slow, confusing, or unconvincing page is still a failing campaign. Good agencies flag this and push for fixes.

Reporting on activity rather than outcomes. Weekly reports that detail what was done rather than what was achieved are a distraction. The question is not “did we add 200 negative keywords this week?” The question is “are we generating more revenue per pound of ad spend than we were last month?”

Underinvesting in ad copy testing. Copy testing is one of the highest-leverage activities in paid search, and it’s consistently underinvested. Tools like Google Ads Editor make it straightforward to manage and test variations at scale. Agencies that run the same ad copy for months without testing are leaving performance on the table.

How Do You Know When It’s Time to Change Your Paid Search Agency?

This is a question most clients sit with for longer than they should. The signs are usually visible well before the relationship ends.

The clearest signal is stagnation. If performance has plateaued and the agency’s response is to run the same playbook harder rather than rethinking the approach, that’s a problem. Good agencies bring fresh thinking when results flatten. They test new campaign types, challenge the account structure, and question assumptions. Agencies that stop doing that have usually stopped investing in your account.

A second signal is communication quality. If your account manager can’t explain what they’re doing and why in plain terms, if reports arrive late or feel templated, if you’re getting different answers from different people at the agency, these are operational red flags.

A third signal is the talent question. The person who pitched you is rarely the person who manages your account day to day. That’s normal in agency life. But if the people managing your account are clearly junior and there’s no senior oversight on strategic decisions, your account is not being taken seriously.

Before pulling the plug, it’s worth having a direct conversation with senior agency leadership about what’s not working. Sometimes that conversation produces real change. Often, it confirms what you already suspected. Either way, you’ll have more information than you did before.

Across the broader topic of paid media, the decisions you make about agency relationships, channel mix, and budget allocation compound over time. The Paid Advertising Master Hub is worth bookmarking if you’re working through these decisions across multiple channels at once.

Should You Build an In-House Paid Search Team Instead?

This is a question that comes up regularly, and the honest answer is: it depends on your scale and your strategic priorities.

In-house teams have advantages. They know your business deeply. They can react faster. They don’t have competing client priorities. And over time, the institutional knowledge they build is genuinely valuable.

The disadvantages are also real. Hiring and retaining strong paid search talent is competitive and expensive. In-house teams can become insular, running the same approaches without the external stimulus that comes from working across multiple accounts and industries. And when a senior practitioner leaves, the knowledge walks out with them.

Many businesses land on a hybrid model: a small in-house team managing strategy and oversight, with an agency handling execution and bringing specialist expertise. This can work well, but it requires clear role definition. If the agency and the in-house team are unclear about who owns what, you get duplication, friction, and wasted time.

The spend level at which in-house starts to make economic sense varies by market and category, but as a rough rule: if you’re spending enough that a dedicated in-house hire would cost less than your agency management fees, the maths are worth running. Factor in the full cost of employment, not just salary, and be realistic about how long it takes a new hire to reach full productivity.

One thing I’d always factor in: the opportunity cost of management time. Running an in-house paid search function requires active leadership attention. That’s time not spent on other strategic priorities. For many businesses, an agency relationship, even an imperfect one, is a better use of leadership bandwidth than building and managing an internal team from scratch.

About the Author

Keith Lacy is a marketing strategist and former agency CEO with 20+ years of experience across agency leadership, performance marketing, and commercial strategy. He writes The Marketing Juice to cut through the noise and share what actually works.

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