Signal-Based Outbound12 min
What is signal-based outbound? The complete guide
Everything about signal-based selling: what it is, which signals exist, and how to set it up.
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Sales Tools
Clay, Apollo, Leadinfo: the tools behind signal-based outbound
11 min read
You know what signal-based outbound is and which buying signals you can use. But which tools do you need? In this article, I compare the most important tools per category — with current pricing, tips and pitfalls.
The 5 categories you need
Signal-based outbound isn't about one tool but a stack. You need five layers: signal detection, prospecting data, website visitor identification, outbound execution and orchestration.
1. Signal monitoring & enrichment
The hub of your signal-based setup. This is where you detect buying signals and enrich contact data.
Clay
Clay monitors buying signals (new hires, funding, tech switches), enriches contact data via 150+ data sources, and routes that data to your outbound tools. Clay's 'waterfall enrichment' automatically tries multiple data sources if the first one doesn't return results.
Prijsindicatie
- Starter: $134/month (24,000 credits/year)
- Explorer: $314/month (120,000 credits/year) — most popular
- Pro: $720/month — for larger teams
Voor wie: B2B teams serious about scaling with signal-based outbound. Clay requires a 1-2 week learning curve, but is a force multiplier after that.
Tip
Start with the Explorer tier. The Starter doesn't have the AI formula generator, which you need for custom enrichments.
Valkuil
Credits run out fast if you filter too broadly. Start with a specific ICP segment and only expand when you know which signals convert.
2. Prospecting & data
Contact data and LinkedIn intelligence. The foundation for your outreach.
Apollo
Apollo combines a database of 275+ million contacts with built-in sequencing. You can search, filter, enrich and email directly from one platform.
Prijsindicatie
- Free: 10,000 email credits/month, 5 mobile credits
- Basic: $49/user/month (annual) — unlimited sequences
- Professional: $79/user/month — built-in dialer
- Organization: $119/user/month (min. 3 users)
Voor wie: Founders and small sales teams wanting an all-in-one for prospecting + outreach. Apollo's free tier is the best free option on the market.
Tip
Use Apollo for data and combine it with Clay for signal detection. Apollo's built-in sequencing is fine for starters.
Valkuil
Mobile numbers and export credits are separately limited. Check how many you need monthly before choosing a tier.
LinkedIn Sales Navigator
Advanced search in LinkedIn's database, saved leads with alerts, and (in the Advanced edition) buyer intent signals.
Prijsindicatie
- Core: $99.99/month (or $79.99 with annual billing)
- Advanced: $179.99/month (or $139.99 annual) — buyer intent, TeamLink
- Advanced Plus: custom pricing, from ~$1,600/year per seat
Voor wie: Everyone doing B2B outbound. Sales Nav isn't optional — it's essential. The Core edition suffices for most.
Tip
Combine Sales Nav with Clay. Clay can pull and enrich LinkedIn data, giving you the best of both worlds.
Valkuil
Watch out for VAT — it's on top of the listed prices and can be 21% extra. InMail credits (50/month on Core) run out fast.
3. Website visitor identification
Who visits your website? This is first-party intent data in its purest form.
Leadinfo
Identifies which companies visit your website. Dutch, GDPR-compliant, cookieless. Identifies 35-40% of B2B traffic in the Benelux — the highest in the EU market.
Prijsindicatie
- From €69/month
- ISO 27001 certified
- 70+ integrations, live within 5 minutes
Voor wie: Dutch and Benelux-focused B2B companies.
Tip
Connect Leadinfo directly to your CRM (HubSpot, Salesforce) so website visits automatically land at the right account.
Valkuil
Leadinfo shows companies, not individuals. You need to find the right contact person yourself — that's where Clay or Apollo comes in.
Leadfeeder (via Dealfront)
Similar to Leadinfo, but with broader international coverage via Dealfront's data ecosystem.
Prijsindicatie
- From €139/month
- Free tier: 100 companies/month, 7 days history
Voor wie: Teams with international clients outside the Benelux.
Tip
For NL focus → Leadinfo. For international → Leadfeeder. Running both simultaneously is rarely needed.
Valkuil
Website visit data is only valuable when you have enough traffic. Below 500 unique visitors per month, it yields too few usable leads.
4. Outbound execution
The tools for sending your messages. Email, LinkedIn, multichannel.
Instantly
Cold email at scale with unlimited mailboxes and built-in warmup. The best value for pure email outbound.
Prijsindicatie
- Growth: $47/month — 5,000 emails/month, unlimited accounts
- Hypergrowth: $97/month — 100,000 emails/month, A/B testing
Voor wie: Teams running volume via email.
Tip
Instantly is NOT a prospecting tool. Connect it to Clay or Apollo for your data. Instantly does one thing well: sending emails with high deliverability.
Valkuil
Lead credits for the built-in database cost extra. Use Apollo or Clay for data, Instantly only for sending.
Lemlist
Multichannel outreach: email + LinkedIn + calls, with AI personalization.
Prijsindicatie
- Email Pro: $69/user/month
- Multichannel Expert: $79-99/user/month — LinkedIn automation, calls, AI
Voor wie: Teams wanting multichannel from one tool. Lemlist's LinkedIn automation is a plus compared to Instantly.
Tip
Lemlist is strong in multichannel. If you only need email, Instantly is cheaper.
Valkuil
Per-user pricing adds up with larger teams. Credits expire monthly without rollover.
La Growth Machine (LGM)
Multichannel sequences via LinkedIn, email and X (Twitter), with visual workflow builder. Popular in the European market.
Prijsindicatie
- Basic: €60/month per identity — LinkedIn + email, 3 campaigns
- Pro: €120/month per identity — + calls, A/B testing
- Ultimate: €180/month per identity — unlimited campaigns
Voor wie: Teams wanting visual workflows and X as a channel.
Tip
LGM is strong in visual campaign builders. Good for teams wanting to build processes visually.
Valkuil
LGM charges per 'identity' (1 LinkedIn + 1 email). With multiple SDRs, that adds up quickly.
5. Orchestration
The glue between your tools. Connects Clay, your CRM, your outbound tool and your signal monitoring into one workflow.
n8n
Open-source workflow automation. Self-hosted or cloud. Powerful but more technical than Make.
Prijsindicatie
- Self-hosted: free
- Cloud: from $24/month
Voor wie: Technical teams wanting maximum flexibility.
Tip
n8n is the most powerful option if you can self-host. Full control over your data and workflows.
Valkuil
Requires technical knowledge. Not suitable if you don't have a developer on the team.
Make (formerly Integromat)
Visual workflow builder. More user-friendly than n8n, with a large ecosystem of integrations.
Prijsindicatie
- Free tier available
- Paid from $10.59/month
Voor wie: Non-technical teams needing to connect tools without coding.
Tip
Start with Make if you need to connect tools that don't have native integrations. The visual builder is intuitive.
Valkuil
Complex workflows can quickly consume credits. Monitor your usage.
HubSpot (Free CRM)
Free CRM with workflows, contact management and basic automation. The free tier is surprisingly complete for small teams.
Prijsindicatie
- Free CRM: €0
- Starter: from €20/month
- Professional: from €890/month
Voor wie: Everyone. HubSpot Free is the best free CRM for B2B.
Tip
Start with HubSpot Free as CRM. Add Make if you need to connect tools without native integrations.
Valkuil
The jump from Free to Professional is large (€0 → €890/month). Plan ahead which features you truly need.
The minimal stack: under €500/month
For a founder or small team wanting to start with signal-based outbound:
| Tool | Functie | Kosten |
|---|---|---|
| Clay (Explorer) | Signal detection + enrichment | ~€290/month |
| Apollo (Free) | Prospecting data | €0 |
| Instantly (Growth) | Email sending | ~€43/month |
| HubSpot (Free) | CRM | €0 |
| Total | ~€333/month |
This gives you signal detection, data enrichment, email outbound and a CRM. Enough to start and validate which signals work.
The premium stack: under €1,000/month
When you know signal-based outbound works and want to scale:
| Tool | Functie | Kosten |
|---|---|---|
| Clay (Explorer) | Signal detection + enrichment | ~€290/month |
| Apollo (Basic) | Prospecting data + sequences | ~€45/month |
| Leadinfo | Website visitor identification | ~€69/month |
| Sales Nav (Core) | LinkedIn intelligence | ~€92/month |
| Instantly (Hypergrowth) | Email at scale | ~€89/month |
| Make (paid) | Orchestration | ~€10/month |
| HubSpot (Free) | CRM | €0 |
| Total | ~€595/month |
Well under €1,000, and you have a complete stack for signal detection, prospecting, website visits, multichannel outreach and automation.
Don't start with everything at once
The pitfall is buying all tools at once and then using 20% of them. Start with the minimal stack, validate your first signal type, and only add tools when you know what works.
The most successful signal-based teams I know started with Clay + one outbound tool. After 2-3 months they knew which signals converted, and only then did they expand. That order saves you hundreds of euros on tools you don't need yet.
Which signals should you monitor?
Discover which buying signals are most relevant for your ICP, or read the complete guide on signal-based outbound.
Ready to transform your outbound?
Book a call. Let's look together at which tools fit your situation and budget.