Lead nurturing is the process of building relationships with potential buyers who aren’t ready to purchase yet, so they choose you when they finally are. In most B2B teams this happens almost entirely by automated email — a drip sequence runs, opens are tracked, and everyone moves on. Yet the warmest contacts a company owns, old enquiries and past customers, usually sit untouched in the CRM. That is an expensive habit: Forrester found that companies which excel at lead nurturing generate 50% more sales-ready leads at 33% lower cost. This guide explains how to nurture B2B leads properly — including the channel most teams have quietly abandoned, and where an AI phone assistant like Sono fits in: the phone.
Nurturing is not the same as chasing. Done well, it respects the buyer’s timeline, stays useful between touchpoints, and reaches people in the way they actually respond to. For high-value B2B deals, that increasingly means mixing email with a real conversation.
What is lead nurturing, and why does it matter for B2B sales?
Lead nurturing covers every deliberate touch you make with a prospect between first interest and a closed deal — emails, calls, messages, useful content, and check-ins. The goal is to stay relevant while the buyer works through a decision that often takes months, not days.
It matters because most leads are not lost, they are simply early. Around 63% of people enquiring about a product won’t buy for at least three months, according to widely cited research from the Brevet Group and Marketing Donut. If your process only knows how to handle “ready now,” you discard the majority of your pipeline by default.
For B2B specifically, nurturing is the difference between a single follow-up and a structured sequence:
- Single follow-up. One email after a demo, then silence. The lead goes cold and a competitor with more patience wins.
- Structured nurturing. A planned series of touches across channels that keeps you top of mind, adds value each time, and prompts the buyer when timing improves.
The economics favour the second approach heavily, which is why lead nurturing is treated as a core revenue function rather than a marketing nicety.
Why email-only nurturing leaves money on the table
Email is the backbone of most nurturing programmes, and for good reason — it scales, it’s cheap, and it’s easy to automate. The problem is that everyone does exactly this, so the average inbox is now a wall of near-identical nurture sequences. Open rates drift down, replies dry up, and your highest-intent leads get the same templated cadence as someone who downloaded a guide by accident.
The channel you’ve probably under-used is the one that cuts through: a direct, well-timed phone call. Calls are harder to ignore than a fourth follow-up email, they surface objections in real time, and they let a prospect feel like a person rather than a row in a sequence. The point isn’t to replace email — it’s to add a human touch at the moments that matter most, and to reserve it for the leads worth the effort.
The best lead nurturing strategies are multi-channel by design: email for consistency and reach, phone for the moments where a real conversation moves the deal forward.
Your warmest leads are already sitting in your CRM
Before spending on new lead generation, look at what you already own. Old enquiries, stalled deals, and former customers are the most overlooked group in any nurturing programme — and the cheapest to convert, because the relationship and the trust already exist. According to Marketing Metrics by Paul Farris, the probability of selling to an existing customer is 60–70%, versus just 5–20% for a new prospect.
Nurturing these dormant contacts back to life is a discipline in its own right — start with lapsed customers and deals that stalled on timing rather than fit. We cover the full playbook, including phone scripts and how to work a whole database, in our guide to lead reactivation. The same logic applies to customers you already serve — when you launch something new, upselling and cross-selling by phone turns the base you own into expansion revenue. The principle for your nurturing strategy is simple: work the contacts you already have before you pay to find new ones.
When should you call instead of sending another email?
Channel choice comes down to intent and timing. Email suits low-effort, ongoing nurturing; a call earns its place when a lead shows a signal or when speed genuinely changes the outcome.
Speed is not a soft factor. The landmark Lead Response Management study published in Harvard Business Review (Oldroyd et al., analysing thousands of leads) found that contacting a new lead within five minutes makes you 21 times more likely to qualify it than waiting 30 minutes, and that 78% of customers buy from the company that responds first. For a fresh, high-intent enquiry, a call beats a queued email every time.
Reach for the phone when:
- A lead takes a high-intent action — requests a demo, replies to a sequence, or revisits your pricing page.
- A deal has stalled and another email clearly won’t restart it.
- You’re reactivating an old contact, where a personal call signals genuine effort rather than a mass send.
- The deal is large enough that the time cost of a call is easily justified.
Keep email for the steady, between-touch nurturing that doesn’t warrant a human yet.
A simple lead nurturing framework that includes the phone
You don’t need complex marketing automation to nurture well. You need a clear sequence, the right channel at each step, and a reason to make contact every time. Here is a framework that works for B2B teams:
- Segment by intent, not just by list. Separate fresh high-intent leads, slow-burn prospects, stalled deals, and past customers. Each group needs a different cadence — treating them identically is why most nurturing underperforms.
- Lead with value, not a pitch. Every touch should give the prospect something — a relevant insight, an answer, a useful comparison — rather than simply asking “any update?”
- Mix channels deliberately. A typical sequence might run: helpful email, a second email with a case example, then a personal call at the point of highest intent, followed by a recap email.
- Personalise the moments that count. Reference the prospect’s situation, the prior conversation, or why you’re calling now. Generic nurturing is easy to ignore; specific nurturing gets replies.
- Always set the next step. Close every touch — call or email — with a clear, low-friction action, whether that’s a meeting, a resource, or a simple “shall I check back in March?”
The aim is consistency without robotic repetition. The teams that win at lead nurturing are not the ones sending the most emails; they’re the ones reaching the right person, on the right channel, at the right moment.
What do you say when you call an old lead?
The opener decides the call. With an old lead or past customer, your advantage is the existing relationship — so use it instead of pretending it’s a cold call.
A reactivation opener that works sounds like this: “Hi Maria, it’s Aleksi from Sono. We spoke back in the spring about handling your inbound calls, and the timing wasn’t right then. I’m calling because [specific reason that’s relevant now] — is this still something on your radar?”
Compare that to the generic version — “Hi, I’m calling to follow up and see if you’re interested” — which gives the prospect nothing to grab onto and invites an immediate brush-off. The first names the prior relationship, gives a reason for calling now, and ends with an easy question. That structure — context, reason, simple ask — is the backbone of any good nurturing call.
How do you nurture leads at scale without hiring more reps?
The honest tension in lead nurturing is this: calls work better than emails, but they don’t scale the way email does. A rep can send 500 nurture emails in a morning; they can’t make 500 thoughtful calls. So the phone gets reserved for the top of the pipeline, and thousands of perfectly warm old leads stay uncalled.
This is where AI voice agents are changing the equation. An AI voice agent can work an entire database of dormant leads and past customers by phone — making consistent, natural, personalised calls at a volume no human team could reach, and handing off to a rep the moment a real opportunity appears. It turns “we’ll get to those old leads eventually” into a campaign that actually runs. For operational B2B teams, that means the cheapest pipeline you own finally gets worked.
You don’t have to rebuild your whole nurturing programme to benefit. Start with one neglected segment — stalled deals, or customers who lapsed last year — give it a clear sequence with a call at the right moment, and measure what comes back. Most teams are surprised by how much warm pipeline was sitting in the CRM the whole time. If you’d like to see what that looks like against your own list, talk to us.
