Marketing agencies in Chicago: 1,571 offices, the types to choose from and who should own your accounts

This report is for Chicago-area companies choosing a marketing agency, people researching the local agency market, and B2B sellers whose customers are agencies.

Chicago's agency market at a glance

The figures cover the Chicago-Naperville-Elgin, IL-IN Metro Area (CBSA 16980) and NAICS 5418, Advertising, Public Relations, and Related Services.

Source: US Census Bureau, County Business Patterns (CBP) 2023. CBP counts establishments with paid employees, not companies: a holding company brand with two Chicago offices counts twice, and a freelancer with no payroll isn't counted. Marketing consultancies (NAICS 541613) sit outside 5418 and add another 1,805 metro establishments.

What kind of agency you're hiring

The Census Bureau sorts agencies by what they mainly do. In Chicago the eight 5418 codes add up exactly to the 1,571 total, and the average size differs a lot by type (employees per location is our calculation):

Two codes outside 5418 matter when you search registries: design-only studios register as 541430 (719 Chicago-area establishments), and the Census Bureau classifies custom SEO services under 541511, custom computer programming. For a full map of the codes, see the NAICS code for marketing.

A long tail and a few very large offices

In three bands: 1,343 establishments have 1 to 19 employees, 173 have 20 to 99 and 55 have 100 or more. The Census Bureau doesn't publish the 1,000-or-more cell for Chicago (it drops any size cell with fewer than three establishments), so the 2 shown is derived as the total less the published cells.

Cook County and the suburbs

The metro's other counties hold the remaining 27 establishments. Cook has 65% of the offices and 76% of the jobs. DuPage stands out: its 201 offices average about 26 employees, against about 22 in Cook and under 10 in Lake County, Illinois.

How to build a Chicago shortlist

1. Write a one-page brief. The outcome you want, the channels, the budget range, the start date and who signs off.
2. Pick the type before the name. Use the table above. A paid search problem needs a 541810 shop with platform experience, not a PR firm.
3. Make a long list of eight to ten. The Chicago Advertising Federation, AMA Chicago and PRSA Chicago are where local agencies and in-house marketers meet. The City of Chicago's business license data lets you filter by business activity: on 30 October 2026, 393 license accounts with an unexpired license listed "Provide Advertising or Marketing Services" or the home-based "Marketing / Advertising / Public Relations" activity, 95 of them home-based. It misses suburban firms and many in the city, so treat it as a starting list.
4. Ask who does the work. At a large office, ask for the names and seniority of your day-to-day team, and what share of your hours goes to freelancers or offshore partners.
5. Call two references, including one client that left, and ask why.
6. Start with a paid project, such as an audit or one campaign, before you sign a retainer.

Who should own the accounts, data and work

Agree ownership before the agency logs in for the first time.

• Google Ads. Google's advertiser guide says a third-party agency "must set up a separate Ads account for you." Keep Admin access yourself: Google's access table lets Admins grant access and unlink manager accounts, and warns that an account with only one administrator risks losing access to its tags.
• Meta. Keep the ad account and Page in your own business portfolio and add the agency as a partner. Meta says a partner with full control "cannot share the business asset with another business"; only the owner can.
• Reporting. Google requires agencies that report monthly to show costs, clicks and impressions at the account level, with Google's charges shown "exclusive of any fees," and to disclose any separate management fee on every invoice.
• Creative. The Copyright Office explains that commissioned work from an outside firm is a "work made for hire" only in nine categories, with a signed agreement. Ask for a written assignment of copyright in final work once it's paid for.

On cost, there's no public Chicago rate card. Stagwell's 10-K says its brands earn "fees for services performed, commissions, and... performance incentives or bonuses," and that its contracts "typically provide for termination by either party within 30 to 90 days." Use that as a benchmark for notice periods.

A note on public companies

The only SEC-registered listed company in the advertising SIC codes (7310 to 7319) with a Chicago address is Groupon, Inc. Its 10-K for 2025 puts its headquarters at 35 West Wacker Drive and reports revenue of $498.4 million. EDGAR files it under SIC 7311, advertising agencies, but it runs a local deals marketplace, not an agency you'd hire. The large holding companies' 10-Ks don't list their Chicago offices.

Selling to Chicago agencies

Agencies here split into a few hundred staffed offices and a long tail of owner-run shops. The 55 establishments with 100 or more employees, and the 49 media buying offices averaging 45 staff, are where finance, media operations and IT buy tools centrally. The 1,343 with fewer than 20 employees buy like small businesses: the founder decides, quickly, and often charges a tool to a client. For method, see how to build a prospect list; at volume, the account research is the slow part, and Bebop does it for each agency in the list.

Subject: Reconciling [client] media invoices

Hi [first name],

[Agency] is hiring a [role, e.g. media billing specialist] in [office], which usually means invoice reconciliation is eating someone's week.

We match media vendor invoices to buys automatically and flag the gaps before month-end close. Agencies your size typically [result you can prove].

Worth 15 minutes on [day] to see whether it fits how [agency] closes the month?

[Your name]

Next step: compare Chicago with the national picture in the largest advertising agencies and how to build a list.