A CPM/CPC benchmark comparator is a tool that sets what you're paying per thousand impressions (CPM) or per click (CPC) against typical figures for the same channel, format and sector, so you can see whether a campaign sits above, below or roughly in line with the market. On its own, a cost figure only tells you what you spent. Set against a benchmark, it tells you whether that spend was reasonable, and whether it's worth changing platform, format or targeting before the budget runs out.
What CPM and CPC actually measure
CPM (cost per thousand impressions) is what you pay for every thousand times an ad is served, whether or not anyone acts on it. It's the standard pricing model for formats built around reach and recognition, such as video, display and out-of-home advertising (OOH), where the job of the ad is to be seen.
CPC (cost per click) is what you pay each time someone clicks through, regardless of how many times the ad was shown to get that click. It's the usual model for paid search and much of paid social, where the objective is traffic to a website or landing page.
The two aren't interchangeable, because they answer different questions. CPM tells you how cheaply you can put an ad in front of people. CPC tells you how cheaply you can move someone from seeing it to acting on it. A campaign can have a low CPM and a high CPC at the same time, if the ad is inexpensive to show but the audience isn't inclined to click.
Why the benchmark matters more than the raw number
A CPM or CPC figure without context is just an invoice. Benchmarking against what similar advertisers typically pay, for the same platform, format and audience, turns that figure into a decision: keep the campaign as it is, adjust the targeting, switch format, or move budget to a different channel altogether. This is why platforms such as IAB UK publish benchmark data, and why platform-reported figures from Google and Meta are worth checking directly.
Benchmarks also move with the calendar. Costs on paid search and paid social tend to rise around periods of heavy retail competition, such as the run-up to Christmas, simply because more advertisers are bidding for the same attention in the same auction. A figure that looks high in October might be entirely normal in November. Comparing your own number against a benchmark from the right time of year matters as much as comparing it against the right platform.
Common mistakes when reading a benchmark
- Treating CPM and CPC as the same kind of number. A CPM benchmark tells you nothing useful about whether your CPC is competitive, and the other way round, because they measure different stages of the same journey.
- Using a global or US-published figure as if it applies here. UK audiences, UK competition levels and UK platform pricing don't track US figures closely, and a benchmark built on American data can make a perfectly reasonable UK campaign look expensive or cheap for no real reason.
- Ignoring the objective behind the number. A campaign built for brand awareness will often carry a different CPM to one built for direct response, even on the same platform, because the audience, format and placement are chosen differently.
- Chasing the benchmark as a target. The benchmark is a range drawn from many advertisers with different creative, different audiences and different levels of competition. Landing exactly on it isn't a goal in itself.
- Comparing figures from different stages of a campaign's life. Costs on a freshly launched campaign often behave differently to a campaign that's been running for weeks, as the platform's delivery algorithm learns who responds.
Using a comparator well
Start by matching like with like: same platform, same broad format, same objective, and ideally a similar sector, before you look at whether your number sits high or low. A CPC that looks steep for retail paid search might be ordinary for a competitive B2B keyword set, so the comparison only means something once the categories line up.
Track the number over time. A single CPM reading tells you where you are today. A run of readings across a few weeks tells you whether a campaign is settling into a stable range or drifting, which is the more useful signal when deciding whether to intervene.
Check when the benchmark data was last reviewed. Advertising costs move with platform changes, seasonal demand and shifts in advertiser competition, so a benchmark that hasn't been checked recently can quietly go stale. Use our CPM & CPC Benchmark Comparator to see how your own figures sit against current reference ranges, and treat the result as a starting point for a conversation about your campaign. Like any tool built on published benchmark data, it can return a figure that doesn't fit your particular situation, so weigh it alongside what you know about your own audience and objective.
Where the reference figures come from
A credible comparator draws on named sources: IAB UK's published benchmark data, platform-reported figures from Google and Meta, and industry reporting on UK ad spend. It's worth asking, of any benchmark you're shown, where the number came from and how recently it was checked, in the same way you'd ask a supplier where a quoted price came from.
If you want to understand how the auction behind CPC pricing actually sets that cost, our guide to how digital ad auctions work covers the mechanics. For a step-by-step walkthrough of the comparator itself, see how to use the CPM & CPC Benchmark Comparator.