The metrics problem

Metric 1: Open rate

What it measures: Percentage of delivered emails that are opened. Indian B2B benchmark: 25 40% for engaged lists. Below 20% indicates deliverability or subject line problem. Above 50% is excellent. What it tells you: Whether your subject lines and sender name are compelling enough to earn a click and whether your emails are reaching the inbox at all (a deliverability problem shows as abnormally low open rate).

Note: Apple Mail Privacy Protection (MPP) inflates open rates for iOS users by pre-loading email pixels. Treat open rate as a directional indicator, not precise measurement.

Metric 2: Click-through rate (CTR)

What it measures: Percentage of openers who click a link in the email. Benchmark: 3 8% for content emails, 1 3% for promotional emails. What it tells you: Whether the body content and CTA are compelling. A good open rate with low CTR means the subject line promised something the email body did not deliver.

Metric 3: Click-to-open rate (CTOR)

What it measures: Percentage of people who clicked after opening (CTR open rate). Benchmark: 10 20% is healthy. What it tells you: The quality of your email content independent of whether the subject line worked. Low CTOR = body content problem. High CTOR with low open rate = subject line problem.

Metric 4: Conversion rate

What it measures: Percentage of email recipients who took the desired action (booked a call, made a purchase, filled a form). Benchmark: Varies by action. For a "book a call" CTA, 1 3% is realistic. For a low-friction download, 5 10%. What it tells you: Whether the full email experience (subject line, body, CTA) is achieving the business goal. This is the metric that connects email to revenue.

Metric 5: Unsubscribe rate

What it measures: Percentage of recipients who unsubscribed from an email. Benchmark: Under 0.5% per send. Above 1% is a warning sign. What it tells you: Whether the email was relevant and expected. A high unsubscribe rate on a specific email signals a mismatch between what the subscriber expected and what they received.

Metric 6: Bounce rate

What it measures: Percentage of emails that could not be delivered. Benchmark: Under 2% for hard bounces. Under 5% for combined. What it tells you: List health. A rising bounce rate means your list contains increasing numbers of invalid addresses. Remove all hard bounces immediately.

Metric 7: List growth rate

What it measures: Net new subscribers per month (new subscribers minus unsubscribes and bounces). Benchmark: 5 10% net monthly growth is healthy for a growing business. What it tells you: Whether your lead generation is keeping pace with churn. A declining or flat list despite ongoing lead generation indicates a high churn problem that needs investigation.

Metric 8: Revenue per subscriber (RPS)

What it measures: Total email-attributed revenue total active subscribers. How to calculate: Requires CRM attribution tag email-originated leads at acquisition, track through to closed revenue. What it tells you: The actual business value of each subscriber the ultimate measure of whether your email marketing system is generating return. Track monthly and look for trend direction.

Frequently asked questions

Which single metric is most important? Conversion rate it is the only metric directly connected to revenue. But it can only be improved if you understand why it is what it is, which requires looking at open rate and CTR together.

How do we track conversion rate if our goal is booking a call (not a purchase)? Use UTM parameters on your Calendly link in the email. In Google Analytics, track goal completions (booking page confirmation). Most email platforms can track link clicks; Calendly and Google Analytics track completions.

What should we do if our open rate suddenly drops? Check deliverability first (MXToolbox, Google Postmaster Tools). Then check for a recent change in sending volume, a new IP address from your email platform, or a recent subject line that may have triggered spam filters.