B2B Marketing Outsourcing: What to Keep In-House and What to Hand Off

B2B marketing outsourcing tends to go wrong at either extreme. A company hands off the thinking along with the typing, and ends up with campaigns nobody inside can explain. Or it keeps everything in-house out of caution, and a small marketing team spends its week learning bid strategies instead of talking to customers.

The fix is a line drawn through the work. Below is where we would draw it: what stays with your team, what an outside partner does better, how the line moves as the team grows, and one rule about ownership that holds at every size.

National advertisers already split the work

The ANA, the Association of National Advertisers, surveys its members about in-house agencies every five years. In the 2023 edition, 82% of members said they have an in-house agency, up from 78% in 2018.

Data table

Measure	Value
of members have an in-house agency	82%
of respondents also work with an external agency	92%
of the work done in-house, on average, among those	61%

Don’t read that as a verdict against agencies. In the same study, 92% of respondents also work with an external agency, and among them an average of 61% of the work is done in-house. According to the ANA, the rest goes out mainly for two reasons. The in-house team is too busy, or the agency has capabilities that do not exist internally.

Gartner’s 2026 CMO Spend Survey adds a budget signal. It reports that CMOs are shifting spend toward paid media, now 31.4% of budgets, funded by cuts to agencies.

Mind who was asked. Most of Gartner’s respondents report more than $1 billion in annual revenue, and the ANA represents national advertisers. So treat these figures as a direction, not a benchmark for a marketing team of five. The direction is plain enough: keep the core, and rent capacity and specialist skills.

What to keep in-house, at any size

Some work gets worse the moment it leaves the building, because it runs on knowledge only your company has.

• Positioning and the core message. An agency can sharpen how you say it. Deciding what you stand for, and for whom, is a leadership call.
• Customer and sales knowledge. The objection that keeps coming up on sales calls, the deal you lost on price, the feature buyers keep asking about. A partner hears all of this second-hand, if at all.
• What counts as a qualified lead. Whoever defines the number should not be the one paid to hit it. The same goes for pipeline.
• Budget decisions. Take advice on where the money should go, then make the call yourself.
• The accounts and the data. Ad accounts, analytics, the CRM and the website logins belong to the company. More on that below.

What is worth handing off

The two main reasons ANA respondents give for sending work out, capacity and missing capabilities, make a good test for a smaller team too. If a piece of work fits neither, keep it.

Work that tends to pass the test:

• Specialist channel execution, such as building and tuning paid search or LinkedIn campaigns, technical SEO and conversion tracking. These skills go stale when nobody on the team uses them often.
• Work that peaks. A product launch, a trade show season or a website migration can swamp a small team for two months. Hire for the peak and you pay for the quiet months too.
• Skills you need a few times a year, like video production, design at volume, or copy written natively for a new market.

What you should not hand off is the judgement behind all of it. A good partner brings a point of view and argues for it. Your team still makes the decision, and still has to be able to explain it to the CEO.

How the line moves with team size

Team size changes what you can keep, not what you should keep. Here is how we see the split work out as a team grows. Treat it as a starting point.

Stage matters as much as headcount. A company still finding its message should keep the writing close, even with a tiny team, because every campaign is also a test of what buyers respond to. Once the message is proven, you can hand off far more of the production. The brief stops changing every month, so a partner can run with it.

Hand off the work, keep the accounts

One rule holds at every size. The ad accounts, the analytics property, the tag manager container, the CRM and the domain sit under your company’s ownership, with your own staff as administrators. The partner gets access. You keep the keys.

It sounds like an admin detail. Then a contract ends, and it decides whether you keep years of campaign history and conversion data or start again from an empty account.

A few habits keep the arrangement honest. Report on pipeline, using your own definition of a qualified lead, so your team and the partner look at the same number. Write down why each piece of work went outside, capacity or capability. And once a year, check whether that reason still holds, because a skill you once rented may now be one you should hire.

If you are weighing a partner for the execution side, the COSEOM® demand generation team works with B2B companies on this split, and our page on inbound B2B lead generation covers the search side of it.

FAQ: B2B marketing outsourcing

What is B2B marketing outsourcing?

Handing part or all of a B2B company’s marketing work to an outside partner, such as an agency, a consultant or freelancers. In our experience, most B2B companies end up doing both: part of the work stays in-house and the rest goes to a partner.

Which marketing work should a B2B company keep in-house?

Positioning and the core message, customer and sales knowledge, the definition of a qualified lead, budget decisions, and ownership of the ad accounts, analytics and CRM.

What should a B2B company hand to an agency?

Work that needs a specialist skill the team uses rarely, such as paid search, LinkedIn campaigns or technical SEO, and work that comes in peaks, such as a launch or a website migration.

Do large companies still use agencies?

Among national advertisers, yes. In the ANA’s 2023 study, 82% of members said they had an in-house agency, and 92% of respondents also worked with an external agency. Among those, an average of 61% of the work was done in-house.

When does a small marketing team need outside help?

When a missing skill is holding back a channel that matters, or when a project is bigger than the team’s week. One or two marketers rarely have time to run specialist channels well on top of strategy and sales support.

Should the agency own our ad accounts?

No. The ad accounts, analytics, tag manager, CRM and domain should belong to your company, with your staff as administrators. The partner is given access.

How do you measure an outsourced marketing partner?

On pipeline, using your own definition of a qualified lead, rather than on activity or form fills. Agree that definition in writing before the work starts.

Is outsourcing marketing cheaper than hiring?

It depends on how often you need the skill. For work that fills someone’s week, a hire usually makes more sense. For a skill you need a few times a year, or extra hands for a peak, paying for the work avoids paying a salary through the quiet months.