What is open rate?

Open rate is the share of delivered messages that were opened: opens divided by deliveries. It measures whether the sender name and subject line earned a look — nothing yet about the content inside. SMS has no open tracking at all, so SMS rows show no value rather than a fake zero.

Formula

open rate = opens ÷ deliveries

Worked example

A campaign delivers 48,500 emails and records 16,000 opens: open rate 33%. A follow-up with a different subject line to a comparable segment opens at 24%. Since audience and offer were held constant, the nine points are the subject line — this A-versus-B use, against your own baseline, is what open rate is still good for.

How Saldo Metrics computes it

fact_messaging_performance stores platform-reported opens and deliveries per campaign or flow-message row; v_messaging_performance divides them per row, and v_flow_performance recomputes the rate from summed totals per automation — never by averaging per-message rates. The opens column is NULL for SMS, and the division propagates that NULL instead of inventing a number. List health uses the all-time average open rate per channel as one of its indicators.

Why it matters

Open rate is the top of the messaging funnel and the earliest signal that a list is disengaging or deliverability is slipping — a slow multi-month drift down often precedes spam-folder trouble. But treat the absolute level with suspicion: privacy features such as Apple Mail Privacy Protection auto-fetch tracking pixels and register opens no human made, inflating the metric unevenly across your list.

Common mistakes

• Treating open rate as engagement truth. Proxy-opens inflate it; a stable 40% can hide a shrinking real readership. Click rate is the harder currency.
• Comparing open rates across lists or eras. Different privacy-feature adoption in the audience moves the number independently of your subject lines; trends within one list beat comparisons between them.
• Optimizing subjects for opens alone. A curiosity-gap subject can lift opens while depressing clicks and raising unsubscribes — judge the whole funnel row.

Where you see this in the app

Marketing → Messaging, as the open-rate column of the campaign table, in the flow waterfall steps, and in the list-health gauges.