Here's the deal: cold emailing and email marketing aren't competitors—they're different tools for different funnel stages. Cold email creates net-new conversations; email marketing nurtures opted-in relationships. Use the right one for your goal, not the one that sounds sexier on a benchmark report.
Move 1: Use cold emailing for top-of-funnel outreach
If your goal is starting conversations with prospects who've never heard of you, cold email is the right tool. According to Belkins' 2025 study analyzing 16.5 million cold emails sent across 93 business domains in 2024, the average B2B cold email reply rate is 5.8%—down slightly from 6.8% in 2023, but still solid for generating net-new leads. Targeting just 1–2 contacts per company pushes reply rates up to 7.8%; blast 10+ people at the same company and it craters to 3.8%. Focus wins.
Worth noting: Belkins is a cold email agency, so these benchmarks come from their own client campaigns. Take them as a directional signal rather than a universal truth. The pattern—tight targeting outperforming spray-and-pray—holds across independent observations of the channel too.
On the ROI side, vendor-funded research (cited secondhand by Salesmotion from Saleshandy) puts cold email returns at $36–$42 per $1 spent. That figure originates from a vendor with a commercial stake in cold email, so treat it as optimistic rather than gospel. The broader point—that cold email is a cost-efficient outbound channel when done well—is well established.
Move 2: Use email marketing to nurture opted-in contacts
If you already have a list of people who raised their hand, email marketing is where you compound that attention. You're not fighting for permission—you already have it. That changes the economics entirely.
Engagement data from MailerLite's 2026 benchmarks report—covering over 3.6 million campaigns sent between December 2024 and November 2025—shows the average email open rate across all industries hit 43.46%. That's a meaningful baseline for understanding list health. Keep in mind this is cross-industry data spanning B2C, nonprofits, e-commerce, and B2B alike; your B2B numbers may look different, but the directional trend still applies.
The honest take on ROI comparisons: you'll see figures thrown around for both cold email and opt-in email marketing that look nearly identical when sourced from vendor benchmarks. Rather than chasing a specific "email marketing ROI" number from a source we can't fully verify, the more defensible claim is this—opt-in email marketing typically costs less per contact to execute than cold outreach, because you're not paying for list building, deliverability infrastructure, or the volume needed to overcome low response rates. Lower cost base plus engaged audience equals stronger efficiency.
So which one do you prioritize with limited resources?
It comes down to one question: do you have an audience yet?
- No audience, no pipeline? Start with cold email. Keep campaigns small and targeted—under 100 recipients per campaign per the Belkins data—and focus on 1–2 contacts per account. Thursday sends in the evening outperformed other windows in Belkins' analysis (6.87% reply rate vs. 5.29% on Mondays).
- Existing list that's gone cold? Reactivation through email marketing is faster and cheaper than rebuilding outbound from scratch. Fix your content before you fix your cadence.
- Both, but stretched thin? Cold email first to fill the top of the funnel, then a simple nurture sequence to keep warm leads from going dark. You don't need a 10-touch content calendar—you need a reason to follow up.
Cold emailing starts conversations. Email marketing deepens them. Neither is inherently "higher ROI" than the other in the abstract—it depends entirely on how well you execute and how relevant your targeting is.