A marketing consultant sets the plan: research, positioning, budget and channels. An agency carries it out: campaigns, content, ads and SEO every month. Choose a consultant when the plan is unclear, an agency when the plan is clear and you lack hands, and both, or one firm doing both, when you need plan and execution.
What a marketing consultant does
A consultant works on the plan and the decisions:
- Researches the market, buyers and competitors.
- Sets positioning, messaging and the offer.
- Chooses channels and splits the budget.
- Builds a plan with targets and a calendar.
- Guides your team or suppliers and reviews results.
What an agency does
An agency works on execution, every month:
- Builds and runs campaigns: search, social, email.
- Writes content and designs creative.
- Runs SEO and website improvements.
- Reports on results every month.
- Supplies specialists you would not hire full-time.
How each is paid
Consultants usually charge by project (a strategy and plan), by day, or by monthly retainer for ongoing guidance. Agencies usually charge a monthly retainer for running channels, or a project fee for builds such as a website.
Clutch's Digital Marketing Agency Pricing Guide 2026 (updated 21 September 2026) says most agencies listed charge $25 to $49 an hour, with SEO, PPC, content, email and social media services in a $100 to $149 hourly band, and reviewed projects mostly between $10,000 and $49,999.
The in-house comparison
The alternative to both is hiring. The Bureau of Labor Statistics puts the median pay for advertising, promotions and marketing managers at $165,780 a year in 2025, and its compensation data puts benefits at 30.0% of private-industry compensation in June 2026, so about $237,000 a year all in, by our arithmetic, before tools and recruiting. One manager rarely covers every channel, which is why many businesses pair a smaller in-house team with outside help.
When a consultant fits
Choose a consultant when:
- You do not know which channels to use or how much to spend.
- Results have stalled and nobody knows why.
- You are entering a new market or launching a new offer.
- You have a team or suppliers who need direction.
When an agency fits
Choose an agency when:
- The plan is clear and you lack people to carry it out.
- You need specialists in several channels.
- You want work running every month with reporting.
- You prefer one monthly cost to several hires.
Using both, or one firm for both
Strategy without execution stays on paper; execution without strategy spends money on the wrong channels. Some businesses hire a consultant for the plan and an agency for the work, with the consultant reviewing the agency. Others hire one firm that does both, which avoids hand-off gaps but puts planning and doing under one roof, so ask how the plan will be judged independently.
Conclusion
A marketing consultant sets the plan; an agency carries it out. Choose a consultant when the plan is unclear and an agency when the plan is clear and you lack hands, and compare both with the in-house option: a marketing manager at the BLS median of $165,780 a year plus benefits. Many businesses need both, either from two firms or one that does both.
PromotEdge International is an international strategy, technology, marketing and design company, and our delivery team is in India. Our marketing strategy work sets research, budget and channel plans, and our digital marketing teams carry them out, together or separately. We travel to our clients every 3 to 4 months.
Facts we rely on: see our company facts for what we state about ourselves and where each fact comes from.