An agency can be the right partner for a defined channel, campaign, or production need. A fractional CMO takes responsibility for the strategic direction those efforts should serve.

The difference is not which option is better in every situation. It is whether the business needs more execution capacity or a leader to set priorities, direct partners, and connect the work to growth.

Many B2B companies need both. The fractional CMO can make agency, vendor, and internal-team work more coherent.

Start with the question of ownership: who is accountable for the marketing function as a whole?