How do multi-contact companies affect targeting logic?

You probably send email at the contact level. One person, one row, one message. Multi-contact companies break that model because the people overlap. Five inboxes, one buying committee, one brand perception. What looks clean at the contact level can look chaotic at the account level.

The core problem. Contact-level logic doesn't know that five addresses share one company. So it sends the same promo to all five on the same Tuesday. Or it suppresses one person for "no engagement" while the account itself just closed a $200K deal through another contact. Your targeting logic is making decisions on incomplete information.

Three places this hits you.

1. Frequency. Five copies of the same email forwarded into one Slack channel is a bad look. Frequency caps need to understand company, not just email address.
2. Suppression. If one person at Acme unsubscribes from marketing, do you keep emailing the other four? Legally yes in most cases. Practically it raises complaint risk and damages the account relationship.
3. Scoring. A lead score that tracks individuals misses account-level momentum. The VP is silent but the three ICs are all reading. That pattern is intent, and contact-level scoring hides it.

Targeting logic that accounts for this groups contacts by domain or CRM account ID, sets a per-company frequency ceiling (often two to four marketing emails per week), and routes different roles into different tracks. A developer and a CMO at the same company should get different language, not a single blast aimed at neither of them.

Tools that help. HubSpot and Marketo treat accounts as first-class objects. ESPs like Klaviyo are adding better domain-level suppression. If your ESP only supports contact-level logic, you'll need a CRM or account-based platform upstream doing the heavy lifting.

Start with the plumbing. Group contacts by company domain, then layer rules for frequency, suppression, and role-based routing. See account-based segmentation and firmographic segmentation for the building blocks.

One prerequisite. Domain-based logic only works when you can trust the domain side of your list. Shared inboxes, typos, and abandoned aliases all pollute the group. Clean the list at the domain level with Review My Emails before you build account rules on top.