Why Hire a Digital Marketing Agency?

Every successful enough business will Google the same question eventually: "why hire a digital marketing agency?"

Most answers are written by agencies trying to sell you. So here’s what I want to do here: give you the guide that I would want to find if I were in your shoes.

The short answer: agencies make sense when you need specialized marketing expertise or execution capacity and you can't justify hiring full-time. But the more meaningful, deeply thought out answer is going to depend on your timing, budget, and ability to manage the relationship.

So let’s talk through all that.

This post covers what agencies are good for, what they cost, when you're ready, how to pick a good one—and if you end up hiring one—how to get the best work out of your agency partner.

Running campaigns across Google Ads, Facebook, email, and landing pages simultaneously requires 40+ hours per week across multiple skill sets. You need someone managing paid search while another handles social, someone else builds email sequences, and another optimizes landing pages. An agency gives you a complete team for the price of one employee—sometimes less.

Conversion optimization, technical SEO, marketing automation, and attribution modeling. These are all skills that take years to develop properly. A full-time specialist costs $80K-$120K+ annually, plus federal and state taxes, worker’s compensation, health insurance, dental insurance, paid time off, and supplies. That’s a lot of overhead.

An agency gives you fractional access to multiple specialists without the long-term payroll commitment. Need a CRO expert for three months? No problem—an agency has one ready.

Long B2B sales cycles with multiple touchpoints, attribution across channels where people see ads, get emails, search Google, then convert weeks later. This is genuinely difficult. Agencies see patterns across dozens of accounts you won't see running just one. They know what normal looks like and when something's actually broken versus just normal variance.

Ad platforms change constantly. Algorithm updates, new features, policy changes—there's always something. Agencies deal with this daily across multiple accounts and ad platforms. They know what works now, not what worked two years ago. When iOS privacy changes tank everyone's Facebook tracking, they've already figured out workarounds.

Agencies know how to make landing pages that convert, and they know how to make ad creative that doesn’t feel fresh out of Canva.

They know how to make email sequences with proper formatting and deliverability. They have templates for dashboards that make sense and are easy to read.

They have documentation and processes that survive when someone goes on vacation.

Sure, this all sounds basic, but most businesses struggle with it.

Even the best agency in the world won’t be able to help you with:

The best agencies know their lane and stay in it. They'll tell you when you're asking for something outside their expertise.

The worst marketing agencies will try to be everything to everyone and end up being mediocre at all of it.

Every marketing agency has a different pricing model. Unless the marketing agency has their prices publicly displayed for specific service packages, you will need to request a quote.

But even saying that, let’s break down the factors that go into digital marketing agency costs.

Agency fees vary wildly—from a few hundred monthly for basic services to six figures for full-suite management of big marketing departments. This covers strategy, execution, reporting, and account management. Smaller agencies or freelancer-style operations run cheaper. Enterprise agencies with big teams cost more.

Separate from agency fees. This goes directly to Google, Meta, LinkedIn, and other platforms. The agency manages it but doesn't take this money—it passes straight through to the ad platforms. This distinction confuses a lot of people who think agency fees include ad spend.

If agency fees exceed your ad spend, the math probably doesn't work. You're spending more on management than actual marketing. The agency should help you deploy capital effectively, not just collect fees.

Agencies are largely self-sufficient, but they are handling your business and they will need to talk to you. So budget 5-10 hours monthly for meetings, reviews, and feedback.

You could hire the single smartest person in the world straight off Madison Avenue, and this fact won’t change: agencies can't read minds. They need your input, decisions, and context. Less involvement means worse results.

There’s also an onboarding period to consider as well. You’ll likely need 30-60 days to get them up to speed on your business, products, customers, competitive landscape, and what you've tried. This isn't wasted time—it's necessary. But it means you won't see results immediately.

The critical question before hiring anyone: Will they generate enough lift to cover their fees? If you can't answer confidently based on your current performance and what improvement seems realistic, you're not ready.

The agency must be meaningfully better than you, month after month, to justify the investment. And sometimes they're not. This is why you need to be able to evaluate performance yourself.

Before you hire a marketing agency, you need to meet all of the first four requirements below, and ideally, the fifth and sixth as well.

If you read this and you find that you can't check all four must-haves, then you're not ready. That's OK, and it’s in this case you will want to revisit this question.

It’s generally not a good idea to spend more than 10-15% of revenue on total marketing. So if you’re making $10K in revenue monthly, it’s not a good idea to hire an agency that charges $3K per month. The math simply doesn't work.

For best results, you need to only work with a marketing agency when you have meaningful revenue. The ideal scenario for a marketing agency should be to help you scale what's already generating money. It’s only if you’re very risk-tolerant that you should be willing to let a marketing agency experiment with your last available dollars in the hopes they get something to work.

If you bill at $300/hour and marketing takes 20 hours monthly, that's $6,000 in opportunity cost. An agency at $4,000/month saves you money even before any performance improvements

But this only works if you or your team genuinely using those 20 hours for high-value work—closing deals, developing products, managing key accounts. If you're scrolling Instagram or reorganizing your desk, it’s a different story.

This is about capacity and leverage.

You need to understand CAC, LTV, conversion rate, ROAS—the basics. You should look at dashboards and tell if things are working. You need to ask intelligent questions when results are off: "Why did CPL jump 40% last week?" or "This channel shows great CTR but no conversions—what's happening?"

If you can't evaluate their work, you won’t be able to know if you’re getting a good deal. That’s not a good situation to be in, as far as you’re concerned. You don't need a marketing degree, but you need enough understanding for informed conversations.

Technical SEO, marketing automation, attribution modeling, conversion optimization—these are specialized skills. Full-time specialists command $80K-$120K+ annually plus benefits. An agency gives you fractional access to multiple specialists without full-time payroll commitment.

Need a CRO expert for a quarter? An automation specialist for a specific project? An agency has them ready. But only outsource specialties after you understand the basics yourself, or you won't know if they're doing good work.

You've made sales, know people want what you sell, conversion rates are non-zero. If you lack product-market fit, agencies can't save you through better marketing tactics. Though they might be able to help you zero in on an offer through exploratory advertising and other forms of offer testing.

Even so, if you have strong revenue (must-have #1), it usually means you've validated something. Agencies, at their best, execute and optimize. Most agencies are playing backhand if asked to figure out what to sell or who to sell it to. (That's your job.)

You've run ads and gotten leads, done Facebook and generated sales. Agencies ideally scale what works, not discover from scratch. So if you can articulate "we get 50 leads at $80 each from Google Ads," that's tremendously helpful.

But if you have the budget and opportunity cost justification, a good agency can help you find what works. The only thing is that you should be prepared for longer timelines and higher costs than scaling something proven.

Here's what most agencies won't tell you upfront: your goals and theirs aren't perfectly aligned. At least not financially.

This is a principal-agent problem. You (the principal) hire them (the agent) to act on your behalf, but incentives differ.

The presence of the principal-agent problem isn’t because agencies are dishonest. It’s just important to say this out loud because this incentive mismatch is a fundamental aspect of how the agency-client relationship works.

It’s in your best financial interest to put up some simple campaigns that generate profit quickly. You want small, fast tests; clear attribution and ROI; and cost-efficiency.

Your agency’s best financial interest is to push for bigger budgets (fees often percentage-based); longer contracts (predictable revenue); and multi-channel campaigns (more complex = harder to replace).

Nobody is wrong here. It’s just important to make sure you and the marketing agency are lined up from day one.

When in doubt, start small, and start with a 90-day pilot on ONE channel with clear metrics. Make sure your marketing agency can communicate what they plan to do and what they expect to happen. They should be able to tell you what to do next if their attempts succeed or if they fail.

What you want is a transparent agency. You want one whose staff will acknowledge misalignment upfront and structure their work with you to make sure everyone benefits. You want someone who will tell you when you're not ready or something isn't working.

And most of all, you’ll want to stay involved. Review performance and don’t be afraid to ask hard questions. Don't abdicate strategy because they're "experts." After all, you're hiring expertise, not magicians, and it’s entirely fair to ask them how the tricks are done.

You might not need a marketing agency. You might need something smaller, like a freelancer or to go the DIY route. Or you might need an in-house hire instead. Here are some other options you have and when you might go another route.

You can hire experts for specific projects like copywriters, media buyers, and developers. This can be done either project-based or part-time.

This works when you know what you need but don't need a full team. It’s often more affordable, easier to start/stop, and has the benefit of direct relationships. But the tradeoff is that you coordinate everyone, and there’s generally less infrastructure than agencies.

This could be a full-time marketing person or team, and works best when you have enough work to keep them busy and want someone who is deeply embedded in your business. A staff member will be fully dedicated to your business and your business alone, will know your industry deeply, and have more aligned incentives than an agencies.

But the tradeoff is that you’re limited to their skillset, have no backup, and hiring (or firing) with a proper W-2 employee is not a fast process.

You can always run small campaigns, write content, and set up your own marketing tracking. This works in the early stage, or when you have a limited budget, or when you want deep understanding of marketing as a discipline.

The benefits of this or that it’s cheap and you will ultimately own the knowledge you earn. And if you choose to hire an agency better, you’ll have an easier time evaluating their work. But this comes with a steep learning curve, time away from other priorities, and the potential for expensive mistakes.

If you’ve looked at the alternatives above and you feel like hiring an agency is still the way to go, here are some red flags, green flags, and questions to ask.

You’ll want to check out your prospective agency’s online presence. I’m talking about Google reviews, Clutch, and industry sites. Take a look at their own marketing, including blog, case studies, social media.

Listen to your gut as well. If you get this nagging feeling that the agency is telling you what you want to hear, they’re probably overselling. Good agencies don’t always tell you what you want to hear. But they’ll always tell you what you need to hear.

And make sure you get along! Chemistry matters because, after all, you’re going to be working together a lot.

So, why hire a digital marketing agency?

It can really help you when you need specialized expertise or execution capacity you can't justify hiring full-time, and you have revenue and ability to manage the relationship.

Agencies make sense when you're scaling what works, opportunity cost is high, you can evaluate their work, and you need specialized skills you can't build in-house. And agencies won’t help when you’re still trying to figure out what you’re selling and to whom.

The best agency relationships are partnerships. Both sides need to understand what agencies are good at (and aren't). And the agency and their client will work together best when they find a way to align their incentives and set clear expectations.

Now, if you read my checklist and you don’t feel ready, that’s OK. It’s fine to wait to hire an agency until after you build revenue, test channels yourself, and get comfortable with basic marketing metrics. In fact, it’s a good thing: you'll be a better client and get better results.

But if you do feel ready and want to discuss whether to hire a digital marketing agency, book a call. I'll honestly tell you if it's the right move or you should wait.