Marketing analytics agencies: what they do, what they cost, who clients trust

Digital analytics is the practice of measuring what people do on your digital touchpoints – website, app, ads, emails, social – and turning it into decisions. It has four layers, and most problems sit in the first one:

Marketing analytics is the part that connects this data to marketing spend: which campaigns, channels and messages produce customers, at what cost.

A digital agency plans, builds and runs a company’s online presence and marketing: websites, search, advertising, social media, email and the data behind them. Most specialise; knowing which kind you are talking to saves weeks:

Tip: ask any digital agency who on its team configures tracking. If the answer is “the developer, when there is time”, you will need a separate analytics partner. On Sortlist, compare specialists in web analytics, Google Analytics consulting and attribution marketing.

1. 1

   Write the measurement plan

   A document listing each business question, the event that answers it and where it is reported. Ask to see one from a past client (anonymised) – if they do not write them, they improvise.

2. 2

   Fix the tracking

   Tags, events, consent mode, server-side tracking, deduplication between platforms. A quick check: does every purchase in your back office appear once – not zero or two times – in your analytics tool?

3. 3

   Build the data foundation

   Export raw data to a warehouse such as BigQuery so history is kept and can be joined with CRM or sales data. Agree up front who pays for storage.

4. 4

   Make reporting useful

   Fewer dashboards, each with an owner and a decision it supports. A good test: ask the agency which three numbers your CEO should see every Monday.

5. 5

   Answer the hard questions

   Attribution, incrementality tests, budget allocation across channels. Insist on a stated method and its limits – no model knows the “true” value of a channel.

These agencies appear on Sortlist’s marketing analytics listing with at least 10 reviews, but have no published analytics project and fewer than 3 reviews describing analytics work. They may be excellent at other services; their ratings simply do not tell you how good they are with data.

1. The sample

Sortlist lists 1,566 marketing analytics providers on this page. We evaluated the 220 agencies on the first three pages of the listing, in its relevance order. 125 of them have at least 10 verified client reviews – our threshold for a rating to be meaningful. 5 of those also pay for a sponsored placement and were set aside, leaving 120. Of these, 21 agencies with at least one published marketing analytics project on Sortlist or at least 3 client reviews describing analytics work were ranked, with 693 verified reviews between them and an average rating of 4.96; the 99 others are listed separately.

2. The score

3. Independence

• Sortlist is a marketplace, not an agency: it does not appear in its own ranking.
• Agencies cannot pay to enter the ranking or to move up. Agencies with a sponsored placement on this listing are excluded from scoring and shown separately.
• The order of the listing page, subscriptions and badges play no part in the score – only the three criteria above.

4. Limits

Reviews reflect each agency’s work across all its services, and agencies with few reviews may be excellent but are not yet scored. That is why every entry says what it is best for – and when another agency would suit you better. The ranking is updated regularly.

On Sortlist, 14 of the 21 agencies in our selection take projects from €1,000, 2 start lower and 5 require €3,000 or more. What you pay depends on which of the five jobs above you need.

Costs that are not in the agency quote

• Server-side tagging hosting: runs on a cloud server you pay for each month.
• Data warehouse: storage and queries are billed by the cloud provider; usually small, but not zero.
• Connectors and BI licences: tools that pull data from ad platforms or display it often charge per user or per source.
• Consent management platform: required in many countries before tracking can fire.

“The big six” usually refers to the six global advertising holding companies that own hundreds of agency brands, including data and analytics units: WPP, Omnicom, Publicis Groupe, Interpublic Group (IPG), Dentsu and Havas.

The list is changing: Omnicom completed its acquisition of IPG on 26 November 2025, creating the largest group by revenue – so some now speak of a “big five”.

For most small and mid-sized companies, these groups are not the practical choice: their analytics teams mainly serve large advertisers with large media budgets. An independent agency or a specialist consultant – like those in our selection – is usually more accessible and more hands-on.

1. Three questions you cannot answer today (e.g. “What does a customer from LinkedIn cost us compared with Google?”).
2. Your stack: website platform, analytics tool, tag manager, CRM, ad platforms, consent tool.
3. Who will use the data: names and roles, and how often they decide something with it.
4. Known problems: numbers that do not match, events missing, reports nobody trusts.
5. Constraints: privacy rules for your markets, data that cannot leave the company, IT approvals.
6. Access you can give: admin rights you will grant – and the list of accounts that must stay in your company’s name.

Send the same brief to three agencies and compare how many of your three questions each proposal actually answers.

• A dashboard demo before any question about your business
• No mention of consent or privacy rules for your markets
• Analytics or tag manager accounts created in the agency’s name
• Attribution promised as “the truth”, with no limits stated
• No documentation of events and tags at handover
• Reports that only show traffic and clicks, never revenue or leads