What does MarketSizer do and how does it work?

MarketSizer shows software vendors which companies are actively in-market to buy their product, qualified by ICP fit, purchase intent, and win probability.

Instead of guessing who to target, you see:

• Which companies are trialling your competitors right now
• Which companies recently churned from incumbents and are evaluating alternatives
• Which companies match your best customers' profiles and are in competitive scenarios where you historically win

MarketSizer qualifies every opportunity across three dimensions before you see it:

• ICP Match:Companies that match your best customers' tech stack and competitive profile
• Purchase Intent: Real signals from trials, churn, and renewals - not anonymous page views
• Win Probability: Historical win likelihood based on subscription outcomes from 50M+ companies in similar competitive scenarios

Stop wasting time on companies that aren't buying. Focus on qualified opportunities you can actually close.

Most intent tools show you behavioural signals (website visits, content downloads, ad engagement). MarketSizer shows you subscription intelligence - which software companies actually use, when they trial alternatives, and historical switching behaviour.

We are not:

• A contact database
• An outsourced SDR team
• An outreach or sequencing tool
• A bulk export tool
• A black-box intent score
• A generic enrichment database (like Clearbit or ZoomInfo)
• A behavioural intent platform (like 6sense or Bombora)

MarketSizer does not replace your sales team. It gives them better accounts to work - subscription intelligence that shows which companies are evaluating, which ones you can win, and when to engage.

See the full side-by-side breakdowns for Apollo, ZoomInfo, 6sense and more on the compare page.

MarketSizer is built for B2B software vendors whose buyers evaluate competitors before they buy. We are live for CRM, customer service, live chat and ITSM vendors (for example Zendesk, Intercom, Freshdesk, LiveChat, Crisp, Gorgias), with marketing automation and sales enablement coming soon.

Specifically, these teams:

• Sales Teams: AEs who need to know which companies are actively evaluating, SDRs and BDRs who want to prospect into accounts that are in-market, and sales leaders who need to prioritise pipeline based on win probability
• Marketing Teams: Demand gen teams running ABM campaigns who need qualified target lists, product marketers who need competitive intelligence, and marketing ops teams who need to enrich CRM data with purchase intent
• Customer Success Teams: CS managers who need early warning when customers trial competitors, account managers looking for expansion opportunities, and renewal teams who want to prevent churn before it happens

If you sell B2B SaaS and struggle to know which companies to target, when to reach out, and which deals you can actually win - MarketSizer is for you.

ICP Match is based on revealed market behaviour, not just firmographics. We look at:

• Competitive context: Which vendors they use, have evaluated, or churned from
• Tech stack patterns: Do they use tools similar to your best customers?
• Historical overlap: Do they match the profile of companies you have won before?
• Structured attributes: Size, industry, geography - used for filtering, not sole determinants

Example: a company might have the “right” size and industry (firmographic match), but if they are using deeply entrenched enterprise incumbents with long contracts, they are a poor ICP fit because they are not realistically winnable.

ICP Match reflects reality - companies that look like your best customers AND are in scenarios you can actually win.

Yes. MarketSizer works for any go-to-market motion:

• Inbound/PLG: Enrich inbound leads with competitive intelligence before your first call, know which competitors they are currently using or trialling, prioritise leads based on ICP fit and win probability, and see if they have churned from a competitor recently (high intent)
• Outbound: Build target lists of companies actively evaluating solutions, know when to reach out based on trial activity, and focus on competitive scenarios where you historically win
• Hybrid models: Use MarketSizer for both - qualify inbound leads faster and identify high-intent outbound targets

MarketSizer works regardless of how prospects find you. It is about qualification, not lead generation.

No. MarketSizer complements your existing stack. What MarketSizer adds that behavioural intent tools do not have:

• Subscription intelligence (which tools companies actually use)
• Competitive context (who they are evaluating, who they churned from)
• Win probability (historical data on which scenarios you win)
• Daily trial detection (not just “someone visited your website”)

Think of it this way:

• Behavioural intent (6sense, Bombora): “Someone at Company X is researching customer support software”
• MarketSizer:“Company X is actively trialling Intercom and Zendesk right now, and you historically win 65% of deals in this competitive scenario”

Best practice: use both. Behavioural intent shows interest. MarketSizer shows action and competitive context. We map exactly how MarketSizer pairs with the tools you already run - Apollo, Clay, Lusha and more - on the compare page.

Currently the platform interface is in English, and we detect subscription signals globally regardless of language.

Data coverage: We track companies worldwide. If they have a public web presence, we can detect it.

We are actively expanding coverage and language support. If you have specific market needs, contact us and we will prioritise based on demand.

MarketSizer shows evidence of what a company is running, not a confirmed contract. A detected product can reflect a live integration or other observable footprint, but on its own it does not prove a current contract, paid plan, renewal date or contract owner.

What this means in practice:

• We detect vendor installations through five detection methods across several sources
• The Opportunity Score rates how promising an account is for you, using ICP Match, Purchase Intent and Win Probability
• We do not publish a single accuracy figure, because accuracy varies by vendor and by how a tool is deployed

How we keep the data reliable:

• Multiple independent indicators (not single data points)
• Live verification combined with historical data
• Daily refresh; new trial signals typically reach your CRM within about 5 days
• Automated quality checks
• Customer feedback loop to improve detection

Important: we do not claim perfect certainty. Every score can be inspected back to the signals that drove it, and every insight includes timelines and supporting signals so you can verify before acting.

MarketSizer is built on proprietary subscription intelligence combining multiple data sources and detection methods to identify which companies are in-market.

Our data foundation includes:

• Evidence-based subscription data: Live and historical software usage across CRM, customer service, live chat and ITSM, with more categories coming, 70M+ subscription outcomes from 50M+ companies analysed over 5+ years, more than 17M active subscriptions monitored today, and daily detection of trials, churn, and switching behaviour
• Competitive context and patterns: Historical win/loss rates across similar competitive scenarios, incumbent displacement patterns and switching timelines, and market-wide adoption and evaluation trends
• Company intelligence: Firmographic attributes for ICP matching, tech stack context relevant to your category, and real-time verification of current environment

Unlike generic data providers, we do not just aggregate information. We qualify every opportunity across ICP fit, purchase intent, and win probability before you see it. Our models are trained on historical subscription outcomes in each category we cover.

When you search for a specific company, MarketSizer verifies their current environment in real-time and shows live and historical data (on-demand lookups).

Daily refresh for bulk data:

• Signals monitored continuously and refreshed daily
• New trial signals typically reach your CRM within about 5 days
• Churn and renewal signals follow the same daily refresh

Trial detection: trials are defined as new installation signals observed within the past 30 days. If a signal persists beyond 30 days, it is treated as an active subscription.

You are seeing current, actionable data - not months-old snapshots. A trial signal is a new installation we first observed in the past 30 days. New trial signals typically reach your CRM within about 5 days of the event.

First: this is expected. No data platform is 100% perfect.

When you find an inaccuracy:

• Flag it in the platform (we have a feedback mechanism)
• We investigate and correct the detection rules if needed, or explain why we think it is right
• You get notified when the issue is resolved
• Our models improve based on your feedback

Why this happens:

• Legacy scripts can remain after tools are removed
• Agencies or shared infrastructure can create misleading signals
• Tools may be deployed only on subsets of pages
• Timing effects (a signal can appear before purchase or linger after removal)

Our philosophy: treat MarketSizer insights as prioritisation signals, not absolute truth. Validate through outreach, then feed corrections back to us. This continuous loop improves accuracy over time.

We monitor vendors across CRM, customer service, live chat and ITSM, with more categories coming. If your competitor is not on the list, let us know.

We continuously add new vendors based on:

• Customer requests
• Market share and relevance
• Technical feasibility of detection

Timeline: most vendor additions take 2 to 4 weeks to implement and validate.

Workaround: even if we do not monitor a specific niche competitor, we can still show you companies in similar tech stack scenarios and competitive contexts.

Most teams see their first qualified opportunities within days of getting started.

Week 1 - Setup and first insights:

• Quick setup process
• Get familiar with how MarketSizer qualifies accounts
• Install the Chrome extension and start seeing companies actively in-market in your category
• Identify high-intent opportunities you can act on immediately

Weeks 2 to 4 - Team adoption:

• Sales team incorporates MarketSizer into their daily workflow
• Marketing builds campaigns around qualified target lists
• CS identifies early warning signals for at-risk accounts

Most common quick win: sales teams identify 10 to 20 high-intent opportunities in their first week and start booking meetings based on competitive intelligence they did not have before.

You do not need months of setup or training. If there are companies in-market right now (and there always are), you will see them immediately.

Yes, absolutely. No credit card required. Your organisation gets 2000 free credits to use over an 8-day trial, which starts when we set up your account.

This lets you:

• See which companies in your market are in-market right now
• Test the accuracy of our data against your own knowledge
• Run a campaign or sales sprint using MarketSizer insights
• Validate that qualified opportunities convert better than your current lists

Want a deeper evaluation? Book a demo and we will show you a custom dataset for your specific competitive scenario.

Yes. MarketSizer has 53 native, click-to-connect integrations, and you can also ask Iggy to connect them for you:

• CRMs: HubSpot, Salesforce, Zoho CRM, Pipedrive, Dynamics 365, Attio, monday CRM and more
• Messaging and email: Slack, Microsoft Teams, Gmail, Outlook, WATI
• Scheduling: Calendly, Google Calendar
• Call intelligence: Gong, Fireflies, Fathom, tl;dv
• Docs and data: Google Sheets, Airtable, Notion, Google Docs
• Outreach: Instantly, Lemlist, Brevo, Mailchimp, Reply.io and more
• Enrichment: Apollo, Lusha, People Data Labs, Hunter, Dropcontact
• Support: Zendesk, Intercom, Freshdesk, ServiceNow and more
• Automation and partnerships: Make, Crossbeam

You can also import trials and closed-won deals from CSV or Excel. The full list is on the integrations page.

Important: you do not need to connect your CRM to use MarketSizer. The Chrome extension works as a standalone tool, and you can also use the MarketSizer web app independently.

MarketSizer shows when your existing customers trial your competitors - typically 3 to 6 months before renewal conversations.

Early warning signals:

• Customer starts trialling Competitor X
• Customer adds new tools to their stack in your category
• Customer shows switching behaviour patterns

Most CS teams find out about churn risk through:

• Declining usage metrics (lagging indicator)
• Negative feedback in QBRs (often too late)
• Surprise non-renewal (way too late)

With MarketSizer, you know as soon as it's detected, usually within about 5 days, when a customer is evaluating alternatives, giving you 3 to 6 months to intervene, address concerns, and protect the relationship.

Bonus: we also show expansion opportunities - where customers use competitors in other regions or product categories you could consolidate.

Yes. MarketSizer shows where your existing customers use competitors in other regions, product categories, or teams.

Example scenarios:

• Customer uses your solution in North America but a competitor in EMEA
• Customer uses your chat tool but a competitor's ticketing system
• Customer's subsidiary in another region uses a different vendor

Your usage data only shows what they are doing with your product. You do not know what competitors they are using elsewhere.

With MarketSizer, you can:

• Bring data-driven expansion recommendations to QBRs
• Show evidence: “We see you are using Competitor XY in Region X. Let us talk consolidation.”
• Prioritise expansion plays based on competitive context

We are a small, focused team building for B2B SaaS GTM teams who are tired of guessing which accounts to pursue.

What we believe:

• Evidence over assumptions: Every claim should be backed by data
• Quality over volume: 100 qualified opportunities beat 10,000 unqualified leads
• Transparency: You should see the evidence behind every insight
• Customer success = our success: We win when you close more deals

How we work:

• Fast iteration based on customer feedback
• Transparent about limitations (we are not perfect, but we are honest)
• Live for CRM, customer service, live chat and ITSM, with marketing automation and sales enablement coming soon - one category at a time, to do each one exceptionally well
• Transparent pricing: you see the credit cost before you unlock anything

Company-level signals first: the core of MarketSizer is company-level subscription signals and business context. Contact-level data, meaning the people at an account and their business email and phone details, is enriched on demand from third-party business-contact providers listed on our subprocessor page, and is automatically anonymised 90 days after enrichment.

CRM integration: Optional and customer-controlled. You decide what data is connected and processed. We never share your CRM data with third parties.

Compliance:

• Our policies and controls are designed to comply with EU and UK GDPR
• SOC 2 Type II in preparation
• Detailed documentation on data handling, retention, and access controls available during procurement

Security reviews: if you need a security review, we provide full documentation as part of your procurement process.