What Is a Marketing Agency? What One Does, the Types, and How to Compare Them
Updated: 5 days ago
A marketing agency is a business you hire to bring you customers through channels such as ads, social media, email, search and your website. It plans the work, runs some or all of those channels for you, and reports on what they brought in. Some agencies cover every channel; others specialize in one, such as search.
You may be reading a proposal right now that covers search, social, ads, email and a website refresh under one monthly figure. This page explains what each kind of agency sells, how to tell them apart on paper, and what to ask before you commit to anyone.
What does a marketing agency do?
A marketing agency's primary roles are to decide which channels can reach your customers, run those channels, and measure which ones bring paying customers. In practice that means planning campaigns, writing and designing the ads, posts and emails, managing ad spend, and reporting what each channel returned.
Role | What it means for you |
Strategy | Deciding who you are trying to reach, and where they are |
Creative | Writing and designing the ads, posts, emails and pages |
Running channels | Placing ads, posting, sending email, working on search |
Measurement | Working out which channel brought paying customers |
What are the different types of marketing agencies?
The types of marketing agency differ by how many channels they run and who their clients are. A full-service agency runs most channels. A digital marketing agency runs the online ones. A specialist agency runs one channel, such as search or social media. A B2C agency works for businesses that sell to the public.
Full-service marketing agency: most channels, including print and events, under one relationship.
Digital marketing agency: the online channels only: search, social media, paid ads, email and your website. A digital marketing agency is a marketing agency that works online.
SEO agency: one channel, being found in search engines. Our page on what an SEO agency is goes further.
Social media or paid ads agency: one channel, run in depth.
B2C marketing agency: any of the above, working for businesses that sell to consumers rather than to other businesses.
What is the difference between an SEO agency and a digital marketing agency?
A digital marketing agency sells reach across many online channels, and its unit of work is a campaign. An SEO agency sells one channel, being found by someone already searching for what you do, and its unit of work is a change to your website or your business profile. SEO is one part of digital marketing.
Digital marketing agency | SEO agency | |
Sells | Reach across many channels | Being found in search |
Unit of work | A campaign | A change to a page or profile |
Answers | How do we get in front of more people? | When someone searches for what I sell, do they find me? |
Capron Media (ours) | Starter does not include Google Business Profile or local listings work, link building, a redesign, social media, ads or email marketing. | Starter: five optimizations a week, made for you on the site you already own. |
SEO work splits into two piles. On your website: the titles and descriptions that appear in a search result, the headings, the words on the page, the links between your pages, page speed, and anything that stops a search engine reading a page. Off your website: your business profile on the map, directory listings, and links from other sites. A line on a proposal that fits neither pile is marketing.
From Capron Media: the free Lite subscription
Choosing a provider? Know where you stand first
See where your site shows up in Google search, and which searches moved since the last check. Lite does not include the work on your site. Starter does.
What does a B2C marketing agency do?
A B2C marketing agency helps a business that sells to the public, such as a shop, salon, restaurant, trade or online store, find and keep customers. B2C means business to consumer. Its work leans on what moves one person deciding quickly: being found in search and maps, reviews, offers, social media and email.
B2C (business to consumer) | B2B (business to business) | |
Who buys | One person, for themselves or their home | A business, often a group of people |
How long the decision takes | Minutes to days | Weeks to months |
What drives it | Need, price, reviews, convenience | Cost, risk, return, relationships |
Main channels | Search, maps, social media, email, ads | Search, email, LinkedIn, sales calls, events |
Is Amazon a B2C company? Mostly, but not only. Its online store sells to consumers, while Amazon Web Services and Amazon Business sell to other businesses. Many large companies are both. If you sell to businesses instead, see our guide to a B2B SEO strategy.
For a small consumer business, the work worth doing first reaches people who are already looking:
Be found in search. Give each service or product a page that says plainly what it is and where.
Keep your Google Business Profile current. Hours, photos, services and replies to reviews. Our guide to expanding your Google Business Profile's reach covers it.
Ask every happy customer for a review. A short link after each job or order does most of the work.
Email past customers. A short, useful message beats a frequent one.
Use social media where your customers are, not on every platform.
Test paid ads with a fixed budget, and stop what does not bring customers.
For a worked example in one trade, see how to market a cleaning business.
Marketing agency vs in-house team: which fits a small business?
An agency gives you several skills for one fee without hiring anyone; an in-house person gives you full attention and control, at the cost of a salary and the work of managing them. For a small business, the question is usually how many channels you need run, and whether one person could cover them.
Option | What it covers | Who does the work | Fits when |
Doing it yourself | Whatever you have time for | You | Your budget is small and you can give it a few hours a week |
A freelancer | Usually one channel | One outside person | You know which channel you need |
A full-service or digital marketing agency | Most channels: social, ads, email, search | A team | You want every channel run and can pay for that |
An in-house marketer | What one person can cover | Your employee | There is enough work to fill the weeks |
Capron Media (ours) | Starter: SEO on your website only, five optimizations a week, made for you on the site you already own | We do, and a person reads every change before it goes on your site | Search is the channel you need. Starter does not include Google Business Profile or local listings work, link building, a redesign, social media, ads or email marketing |
How do I tell which kind of agency I am looking at?
Read the proposal for its unit of work. If the deliverables are campaigns, reports and managing channels, you are reading a marketing retainer, perhaps with search inside it. If the deliverables are named changes to named pages and to your profile, you are reading SEO.
Then ask which lines would still be there if you only wanted search. That answer is the search work. The rest is marketing, and it should be priced and judged as marketing.
Two checks you can run on any agency, including us
Sort the proposal's services into two columns: what you could count at the end of the month, and what you could not. A list of changes to named pages, each with a date, is countable. Ongoing strategy is not. Four posts a week is countable. Brand presence is not.
Then ask to see last month's list, written at the time the work was done, with dates. A list written as the work happened is hard to fake afterwards. A provider who is new and has no month to show should say so, which is a better answer than a list put together for the meeting.
Run the same two checks on Capron Media. What a subscription covers, and what it does not, is set out line by line on our pricing page.
How do I compare marketing agencies?
Ask every agency on your list the same five questions, and write the answers side by side.
What is the unit of work? Campaigns, or named changes to named pages?
What can I count at the end of the month? Ask for last month's list.
Can the price be split by channel? If not, you cannot compare it with a single-channel quote.
Is ad spend inside the fee or on top of it? This line can catch people out.
What is the commitment? A month, a year, or longer?
If search is the channel you care about, our longer walk-through is how to choose an SEO agency.
How much does a marketing agency cost?
There is no single figure worth quoting for the market, because the price depends on what is in the bundle. What moves it:
The number of channels, because each one is somebody's time
Whether the agency makes the changes, or hands you a list to make yourself
Whether ad spend sits inside the figure or on top of it
The length of the commitment
On a bundle, ask for the figure split by channel. If it cannot be split, you cannot cancel the half that is not earning its place.
Who are the biggest marketing agencies?
The biggest names are advertising holding companies, which own many agencies under one parent. When Omnicom completed its purchase of Interpublic in November 2025, the trade site Mediaweek reported that it moved ahead of Accenture Song and WPP to become the largest agency group worldwide. Lists of the "big three" or "big four" differ by how they count.
None of them is built for a small business. They serve national brands; a local shop is better served by a small agency, a freelancer or a focused service.
Before you commit to anyone
Sort the proposal into countable and not, ask for last month's list, and ask for the price split by channel. If the bundle still makes sense for your business after those three steps, buy the bundle. If only the search half does, buy the search half, from them or from someone else.
If someone in-house has an evening a week, do it yourself and buy nothing yet. If that evening does not exist, what you are buying from anyone is that the work keeps happening in month four, which is the argument in our guide to ongoing SEO.
Starter is the search work on your website: one website per subscription, five optimizations a week, and no contract; leave any month. The business profile and off-site work are on its not-included list. What it costs is on our pricing page, and more about how Capron Media works is on our home page.
And if the proposal on your desk is a bundle and you want to know which lines are search before you decide, book a free call about your site. It takes about 15 minutes, and it is about whether we are a fit for you.
From Capron Media: the free Lite subscription
Check any website, a provider's or your own
Your own site doesn't use up a check. You can check up to three other sites, each once every 30 days. Lite does not include the work on your site. Starter does.
If you would rather have the work done for you, Starter is five optimizations a week, made for you on the site you already own, and each one shown in your portal. See every price.
Written by Spencer Capron, founder of Capron Media, a Middleborough, Massachusetts SEO service for small business owners. Spencer is HubSpot SEO II certified, holds CompTIA Security+, and has run recurring SEO programs for 30+ small-business clients. He wrote this post in collaboration with our AI agents, and he reviews everything published here.
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