What Is Email Marketing? Email marketing returns $36 for every $1 spent — a figure confirmed by Litmus in its 2025 State of Email report. No other digital channel comes...

What Is Email Marketing?

Email marketing returns $36 for every $1 spent — a figure confirmed by Litmus in its 2025 State of Email report. No other digital channel comes close at scale. Yet many business leaders still treat email as a broadcast mechanism: send a newsletter, move on. That is the wrong frame entirely. Email is a relationship management system. It moves prospects through a buying journey, retains existing customers, reactivates lapsed ones, and does all of this at a unit economics that paid media cannot match. Understanding what email marketing actually is — and what it can do — is the starting point for deploying it strategically.

Key Takeaways

• Email marketing returns $36 for every $1 spent on average, rising to $42 for brands using advanced personalisation (Litmus, 2025).
• Automated email flows represent just 2% of send volume but drove 37% of all email-generated sales in 2024 (Klaviyo, 2025 Benchmark Report).
• Segmented campaigns can achieve up to 760% more revenue than broadcast sends — making audience strategy the primary lever of performance.
• Australian businesses operating under the Spam Act 2003 must obtain consent before sending and honour unsubscribe requests within five business days.

What Is Email Marketing and How Does It Work?

Email marketing is the practice of sending commercial messages to a consented list of recipients with the intent of driving a business outcome — whether that is a sale, a consultation booking, a renewal, or a referral. According to HubSpot’s 2025 State of Marketing report, 87% of B2B marketers name email as their top free organic channel. Permission is the operational foundation. Without documented consent, there is no email programme — only liability.

The mechanics are straightforward: a business builds a list of subscribers who have opted in to receive communication. Those subscribers receive messages matched to where they are in the customer relationship. The messages range from high-frequency promotional sends to single-trigger transactional confirmations. The sophistication lies not in the technology but in the strategy behind each send.

There are four primary types of email that a mature programme deploys:

• Newsletter emails — regularly scheduled content that builds authority and keeps a brand present in a subscriber’s inbox. Frequency creates familiarity; consistency creates trust.
• Promotional emails — time-bound offers, product launches, event invitations, and campaign-specific content designed to drive immediate action.
• Transactional emails — order confirmations, account notifications, password resets, and delivery updates. These carry the highest open rates of any email type because the recipient is actively expecting them.
• Automated emails — behaviour-triggered sequences sent based on a subscriber’s action or inaction. Welcome series, abandoned cart reminders, post-purchase follow-ups, and re-engagement flows all fall into this category.

The common misconception is that email marketing requires a large list to deliver results. It does not. A small, well-segmented list of 2,000 engaged subscribers will outperform a neglected database of 50,000. Audience quality, not quantity, determines programme performance.

Email marketing operates on owned infrastructure. Unlike social media reach or paid search placement, an email list belongs to the business that built it. Platform algorithm changes, ad cost inflation, and account suspensions do not affect a consented subscriber database. That ownership is a strategic asset that compounds in value over time — something no rented audience can replicate.

What Are the Key Email Marketing Metrics?

In 2025, the average email open rate across all industries reached 43.46%, up from 42.35% in 2024, according to MailerLite’s 2025 benchmark analysis. That figure is directionally useful but must be read with context: Apple’s Mail Privacy Protection pre-loads tracking pixels for users on Apple Mail, inflating open rate figures across the industry. The metrics that matter most are those tied directly to revenue and list health.

Measuring the right indicators is not a technical exercise — it is a strategic discipline. The following table maps each core metric to its industry benchmark and what it actually measures about programme performance.

A high open rate paired with a low click-through rate signals strong subject lines but weak body content or offers. A low unsubscribe rate paired with a low conversion rate may indicate that the list is passive — subscribers are staying but not buying. Reading these metrics together, rather than in isolation, is where strategic insight lives.

List decay is a metric most programmes ignore until it becomes a deliverability crisis. In 2024, an average of 9% of subscribers unsubscribed annually and a further 7% became non-deliverable due to hard bounces — a combined annual list loss of approximately 16% before a single new subscriber is acquired. A programme with no active list growth strategy is a programme in decline.

What Is Email Segmentation and Why Does It Matter?

Segmented email campaigns generate up to 760% more revenue than broadcast sends, according to data widely cited from Campaign Monitor’s research. That is not a marginal improvement — it is a structural difference in what the channel can produce. Segmentation means dividing a subscriber list into distinct groups based on shared attributes — purchase history, industry, geographic location, engagement level, or stage in the buying cycle — and sending each group content matched to their context.

The logic is straightforward: a prospect who downloaded a pricing guide has different needs than a customer who purchased six months ago and has not returned. Sending both the same promotional email is wasteful at best and damaging to the relationship at worst.

Personalisation extends segmentation from audience grouping to individual-level relevance. Personalised subject lines alone increase open rates by 26%, according to research aggregated by Mailmodo. When personalisation extends into the email body — product recommendations, content matched to browsing behaviour, first-name addressing — the performance gains compound. Litmus data shows that brands using advanced personalisation achieve an average email ROI of 43:1, compared to 12:1 for those that never personalise.

Effective segmentation does not require sophisticated technology to start. Basic behavioural segmentation — separating active openers from inactive subscribers, or separating buyers from non-buyers — can be implemented in any mainstream email service provider and delivers immediate performance improvements. The strategic error is treating segmentation as an advanced tactic rather than the baseline operating model.

According to DMA research, 77% of email marketing ROI comes from segmented, targeted, and triggered campaigns. The implication is direct: if a programme relies primarily on broadcast sends to the full list, it is leaving the majority of its potential return unearned.

What Is Email Automation and How Does It Drive Revenue?

Automated email flows — sequences triggered by subscriber behaviour rather than a scheduled send date — represented just 2% of total email volume in 2024 but generated 37% of all email-attributed sales, according to Klaviyo’s 2025 Benchmark Report. That ratio illustrates the commercial leverage available through automation: a relatively small number of well-constructed sequences, operating without manual intervention, producing a disproportionate share of revenue.

The highest-performing automated sequences fall into four categories:

• Welcome series — triggered when a subscriber first joins the list. Klaviyo’s 2025 data shows welcome flows average a revenue per recipient (RPR) of $2.65, with top 10% performers reaching $21.18 RPR. The welcome sequence sets expectations, delivers on the opt-in promise, and begins the brand relationship.
• Abandoned cart flows — sent when a prospect adds items to a cart but does not complete the purchase. Klaviyo’s 2025 data shows abandoned cart flows deliver the highest RPR of any automated sequence at $3.65 average, with top performers reaching $28.89 RPR. Brands on the Klaviyo platform see 50.5% average open rates for cart abandonment flows.
• Post-purchase sequences — sent after a completed transaction to confirm the order, set delivery expectations, cross-sell complementary products, and request reviews. These extend the customer relationship beyond the transaction.
• Re-engagement flows — targeted at subscribers who have not opened or clicked within a defined window, typically 90–180 days. A well-constructed re-engagement sequence recovers a portion of a lapsing audience and allows clean removal of those who do not respond, protecting deliverability.

The strategic advantage of automation is not speed — it is precision. A human operator cannot send the right message to every subscriber at the right moment in their individual journey. Automation can. Each subscriber experiences the sequence on their own timeline, triggered by their own behaviour, which is why automated emails generate up to 30 times more revenue per recipient than equivalent broadcast campaigns, according to Klaviyo’s benchmark analysis.

For B2B programmes, automation typically covers different trigger points: content downloads initiating a nurture sequence, webinar attendance triggering a follow-up series, or trial expiry prompting a conversion push. The underlying logic is identical to e-commerce automation — match the message to the moment in the relationship.

What Are Email Marketing Compliance Requirements?

Regulatory compliance is not optional in email marketing, and it is not a minor administrative consideration. In Australia, the Spam Act 2003 (Cth) — enforced by the Australian Communications and Media Authority (ACMA) — imposes specific obligations on any business sending commercial electronic messages. The ACMA issued more than AUD 15 million in spam and telemarketing fines in the 18-month period to mid-2024, demonstrating that enforcement is active, not theoretical.

Note: The following is general awareness information only and does not constitute legal advice. Businesses should seek qualified legal counsel to confirm their specific compliance obligations.

Three frameworks govern the majority of email marketing programmes globally:

• Australian Spam Act 2003 (Cth) — Requires documented consent before sending any commercial electronic message, clear sender identification in every email (including legal business name and ABN), a functional unsubscribe mechanism in every message, and processing of unsubscribe requests within five business days. Australia’s consent-first framework is closer to GDPR than to CAN-SPAM.
• GDPR (EU) — Applies to any business sending to EU-based recipients regardless of where the business is located. Requires explicit consent, a clear basis for data processing, the right to erasure upon request, and transparent privacy policies. Non-compliance penalties can reach 4% of global annual turnover or €20 million, whichever is greater.
• CAN-SPAM Act (US) — Operates on an opt-out rather than opt-in basis, making it more permissive than Australian or EU frameworks. Still requires accurate sender identification, non-deceptive subject lines, a clear unsubscribe mechanism, and prompt processing of opt-out requests within 10 business days.

The practical implication for Australian businesses is that consent must be captured at the point of opt-in, documented, and maintained. Purchased email lists are incompatible with the Spam Act’s consent requirements. Every commercial send must include a working unsubscribe link, and that link must resolve to an action — not a form requiring account creation or personal information beyond an email address.

Compliance is not a constraint on effective email marketing. A consented list of subscribers who chose to hear from a business is a more valuable asset than a large unconsented database. Permission is the precondition for trust, and trust is the precondition for conversion.

Frequently Asked Questions

What is a good email open rate?

Industry benchmarks for 2025 place the average email open rate at 43.46% across all sectors, per MailerLite’s analysis. However, Apple’s Mail Privacy Protection inflates these figures by pre-loading tracking pixels. A more reliable proxy for engagement is click-to-open rate (CTOR), which averaged 6.81% in 2025 and is unaffected by MPP distortion.

How often should a business send marketing emails?

Send frequency should be governed by the value delivered in each email and the expectations set at opt-in. Research from HubSpot indicates that sending more than five emails per week risks elevated unsubscribe rates. Most B2B programmes perform well at one to two sends per week. Automated trigger-based emails sit outside this frequency consideration and are governed by subscriber behaviour rather than a schedule.

What is the difference between email segmentation and personalisation?

Segmentation divides a list into groups sharing common characteristics — industry, purchase history, geographic location — and sends each group relevant content. Personalisation applies individual-level data within those groups: first-name fields, product recommendations based on past behaviour, or dynamic content blocks. Litmus data shows combined segmentation and personalisation achieves 43:1 ROI versus 12:1 for non-personalised sends.

Is email marketing still effective in 2025?

Email marketing remains the highest-ROI channel in digital marketing. Litmus’s 2025 State of Email report confirmed an average return of $36 per $1 spent across all industries. Automated flows, per Klaviyo’s 2025 Benchmark Report, generated 37% of all email-attributed sales while representing only 2% of send volume — a performance ratio no other marketing channel matches at comparable cost.

What platforms do businesses use to send email marketing?

The market is segmented by use case. Klaviyo dominates e-commerce automation, with its 2025 Benchmark Report drawing on data from hundreds of thousands of brands. HubSpot and ActiveCampaign lead for B2B CRM-integrated programmes. Mailchimp, MailerLite, and Brevo serve small to mid-sized businesses. Platform selection should follow programme requirements — automation depth, CRM integration, and list size — not brand recognition alone.

Conclusion

Email marketing is not a legacy channel. It is the highest-ROI mechanism available in digital marketing, with a $36 return per $1 spent confirmed by Litmus in 2025, a 760% revenue uplift available through segmentation, and automated flows that generate 37% of email revenue from just 2% of send volume. The gap between businesses that treat email as a broadcast tool and those that treat it as a managed relationship system is measurable — in open rates, conversion rates, and ultimately in revenue.

The starting point is not technology. It is strategy: define the audience, establish consent, build sequences that match messages to moments in the customer relationship, and measure the metrics that connect directly to commercial outcomes. For businesses operating in Australia, compliance with the Spam Act 2003 is both a legal obligation and a strategic advantage — a consented list is a trusted list, and a trusted list converts.

[INTERNAL-LINK: email marketing strategy guide → comprehensive guide to building and scaling an email marketing programme for B2B businesses]

Sources

• Litmus, State of Email 2025, litmus.com/state-of-email-reports, retrieved 2026-05-26
• Klaviyo, 2025 Benchmark Report (AMER), klaviyo.com/marketing-resources/ecommerce-benchmarks, retrieved 2026-05-26
• MailerLite, Email Marketing Benchmarks 2025, mailerlite.com/blog/compare-your-email-performance-metrics-industry-benchmarks, retrieved 2026-05-26
• HubSpot, Email Marketing Benchmarks by Industry, blog.hubspot.com/sales/average-email-open-rate-benchmark, retrieved 2026-05-26
• Campaign Monitor / DMA, segmentation revenue impact data, retrieved 2026-05-26
• Mailmodo, Email Segmentation Statistics 2025, mailmodo.com/guides/email-segmentation-statistics, retrieved 2026-05-26
• ACMA, Avoid Sending Spam, acma.gov.au/avoid-sending-spam, retrieved 2026-05-26
• ACMA, Email and SMS Unsubscribe Rules Fact Sheet, acma.gov.au, May 2024, retrieved 2026-05-26