A paid marketing agency buys attention for you: search ads, paid social, shopping feeds, display and retargeting, plus the creative and landing pages that carry them. The purchase confuses buyers because two very different things sit inside one invoice. One is media, the money that goes to Google, Meta or a retail network and never touches the agency. The other is management, the fee the agency keeps for planning, building, testing and reporting on that media. Judge those separately, because a cheap management fee attached to careless media buying is the most expensive arrangement on this page. What follows is how the fee models differ, what access to insist on before you sign, and which claims to test against published guidance rather than a pitch deck.
Media, management and creative are three purchases
Media is pass-through spend. Management is the agency's fee for running it. Creative, meaning ad copy, video, static assets and the landing pages the traffic hits, is sometimes bundled and sometimes billed separately, and the difference can be several thousand dollars a month on the same scope. Ask a candidate to break a proposal into those three lines before you compare it with anyone else's, because agencies quote them combined in whatever way makes their headline number look smallest. The landing page question matters more than most buyers expect: an agency that only touches the ad platform and never the page has handed you a conversion problem it cannot fix, and will report cost per click when you asked about cost per customer. If your site team is slow, say so during the pitch and see whether the agency offers to host or build pages itself.
How the fee is structured, and what each model rewards
Four models dominate. A percentage of media spend is simple and scales with the account, but it rewards spending more, not spending better. A flat monthly retainer is predictable and rewards efficiency, though it can leave the agency under-resourced if your spend grows fast. A hybrid, a base retainer plus a smaller percentage above a spend threshold, is the common compromise. Performance pricing, a fee per lead or a share of tracked revenue, sounds aligned but shifts the argument to attribution: you will spend the relationship debating which conversions the agency caused. Whichever model you pick, get the specifics in writing: what happens when spend doubles, what happens when it halves, whether creative production is inside the fee, and what the notice period is. Ask for the fee as a dollar figure at your actual budget, not as a rate.
Own the accounts, the pixels and the data
The single clause that decides how a bad engagement ends is account ownership. Your business should own the ad accounts, the conversion tracking, the analytics property and the audience lists, with the agency granted access as a user rather than as the account owner. Agencies that run your ads inside their own manager account can, and sometimes do, take the history with them when the relationship ends, and the historical performance data is what makes the next agency effective quickly. Put in the contract that accounts and data assets are yours, that access will be transferred back within a stated number of days after termination, and that the agency will document the tracking setup it built. This costs nothing to agree at signature and is close to impossible to win afterwards.
Claims to test before you sign
Google's own guidance on hiring search help is the cheapest vetting checklist available: ask for examples of previous work and success stories, ask what results are expected and in what timeframe, and be wary of anyone who claims a special relationship with Google or refuses to explain their methods. Google states plainly that nobody can guarantee a top ranking, and a paid media pitch that promises a fixed cost per lead by a fixed date deserves the same scepticism, since the auction price is set by competitors you do not control. On the advertising side, the Federal Trade Commission requires that objective claims in advertising be truthful and substantiated before they are made, which applies to the ads the agency writes for you and to the results claims the agency makes about itself. Ask for one reference in your industry and call it. When you compare paid search marketing services across a shortlist, the differences that matter are fee structure, account ownership and the substantiation behind the case studies, not the polish of the deck.
Questions people ask about paid marketing agency
Is a percentage of ad spend a fair way to pay an agency?
It is common and workable at steady budgets, but it rewards larger spend rather than better spend. If you use it, cap the rate at higher tiers and agree in advance what happens if you pause a channel. A flat retainer or a hybrid removes the incentive problem, at the cost of some flexibility.
Should the agency own my Google Ads account?
No. Your business should own the ad account, the conversion tracking and the audience lists, with the agency added as a user. Agree in the contract that access reverts to you within a set number of days after termination, along with documentation of the tracking setup.
Can an agency guarantee a cost per lead?
Not honestly. Auction prices move with competitor bidding, seasonality and your own conversion rate. Google says nobody can guarantee a ranking, and the same logic applies to paid results. A credible agency forecasts a range, states its assumptions, and reports against them.
How long before paid campaigns are worth judging?
Long enough to gather statistically meaningful conversion data, which depends on your volume rather than the calendar. Agree the judging window and the metric at the start, and insist that early reporting shows leads and revenue, not just impressions and clicks.