A tag is a short label attached to a contact to record something about them: an interest (“vegetarian”), a source (“expo-2026”), an action (“attended-webinar”) or a status (“vip”). A contact can carry many tags at once, and tags can be added or removed by hand, by imports, by forms, by integrations or by automations.
Tags are flexible because they need no setup. A field such as “city” holds one value per contact and suits data every contact has. A tag is either present or not, so it suits yes-or-no facts that apply to some contacts, and you can create new ones whenever you need them. Lists, by contrast, usually represent what someone subscribed to, along with its consent and sender settings.
Their real power is in segments and automations. A segment like “has tag ‘yoga’ AND not tag ‘member’” finds interested non-members in seconds. An automation can start when a tag is added, for example sending a thank-you email when someone is tagged “attended”, or add a tag at a point in a journey so you can find those people later.
Tags get messy without a little discipline. “Diwali sale”, “diwali-sale” and “DiwaliSale2025” end up as three separate tags. Agree a simple naming pattern, use lowercase with hyphens, add dates or years for one-off events, and delete tags nobody uses. A short shared list of tag meanings saves confusion when several people work on the same account.
A Chennai event organiser tags everyone who scanned in at its October food festival with “attended-oct-fest”. A post-event automation starts when that tag is added, sending a thank-you email with a feedback link the next day. Later, the tag helps build a segment of past attendees for the next festival’s early-bird offer.
MailNesto supports unlimited tags on contacts, automations that start when a tag is added, conditions and segments based on tags, and conditional email blocks that show only to tagged contacts.