Company lists · Data refreshed September 2026

Top 25 Sales engagement platform developers based in the United States

RevenueBase identified 1,479 sales engagement platform developers headquartered in the United States as of September 2026 and tracks 38,671 professional contacts across them, including 12,884 with verified work emails and 10,041 with mobile numbers. San Francisco is the largest hub.

This list covers sales engagement platform developers headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 6, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 6, 2026 86% judged on-target in blind review
1,479Companies
38,671Contacts tracked
12,884Verified emails
10,041Mobile numbers
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The 25 largest sales engagement platform developers based in the United States

Ranked by team size
Top 25 of 1,479 sales engagement platform developers based in the United States, ranked by team size, largest first. Data refreshed Sep 6, 2026. RevenueBase Smart Search rates how each company's information relates to sales engagement platform developers: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceBoston, MA, United StatesHQ checked Sep 6, 20261,001-5,0002,789 contacts →

Indirect evidence

“Klaviyo (NYSE: KVYO) is the autonomous B2C CRM.”

Source: RevenueBase Database · checked Sep 6, 2026
2Partial evidenceOgden, UT, United StatesHQ checked Sep 6, 20261,001-5,0002,446 contacts →

Partial evidence

“MarketStar is a global B2B sales outsourcing leader with 38+ years of experience driving predictable revenue growth.”

Source: RevenueBase Database · checked Sep 6, 2026
3Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 6, 20261,001-5,0001,443 contacts →

Indirect evidence

“6sense is on a mission to revolutionize the way B2B organizations create revenue by predicting customers most likely to buy and recommending the best course of action to engage…”

Source: RevenueBase Database · checked Sep 6, 2026
4Partial evidenceSeattle, WA, United StatesHQ checked Sep 6, 2026501-1,0001,281 contacts →

Partial evidence

“Outreach, founded in 2014, is the only complete agentic AI platform for revenue teams.”

Source: RevenueBase Database · checked Sep 6, 2026
5Indirect evidenceSan Diego, CA, United StatesHQ checked Sep 6, 20261,001-5,0001,256 contacts →

Indirect evidence

“Seismic is the global leader in enablement, helping organizations engage customers, enable teams, and ignite revenue growth.”

Source: RevenueBase Database · checked Sep 6, 2026
6Indirect evidenceMiami, FL, United StatesHQ checked Sep 6, 2026201-5001,068 contacts →

Indirect evidence

“CIENCE Technologies, Inc, founded in 2015 and headquartered in Denver, CO, is a pioneering global company in lead generation software and services, committed to transforming the…”

Source: RevenueBase Database · checked Sep 6, 2026
7Partial evidenceNew York, NY, United StatesHQ checked Sep 6, 2026501-1,000970 contacts →

Partial evidence

“Founded in 2010, Pipedrive is an easy and effective sales CRM that drives small business growth.”

Source: RevenueBase Database · checked Sep 6, 2026
8Strong evidenceSan Francisco, CA, United StatesHQ checked Sep 6, 2026501-1,000863 contacts →

Strong evidence

“Apollo.io is the AI-powered end-to-end go-to-market platform that empowers sales, marketing, and revenue teams to find prospects, engage customers, and close deals with…”

Source: RevenueBase Database · checked Sep 6, 2026
9Indirect evidenceTysons, VA, United StatesHQ checked Sep 6, 2026501-1,000825 contacts →

Indirect evidence

“memoryBlue is the go-to partner for revenue leaders in B2B Tech looking to grow their pipeline engine.”

Source: RevenueBase Database · checked Sep 6, 2026
10Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 6, 2026501-1,000622 contacts →

Indirect evidence

“ON24, a Cvent company, is on a mission to help businesses bring their go-to-market strategy into the AI era and drive cost-effective revenue growth.”

Source: RevenueBase Database · checked Sep 6, 2026
11Indirect evidenceDenver, CO, United StatesHQ checked Sep 6, 2026501-1,000576 contacts →

Indirect evidence

“SugarAI: the CRM that actually helps sellers sell.”

Source: RevenueBase Database · checked Sep 6, 2026
12Strong evidenceSan Jose, CA, United StatesHQ checked Sep 6, 20261,001-5,000572 contacts →

Strong evidence

“Adobe Marketo Engage offers the leading Engagement Platform that empowers marketers to build brand value, grow revenue, and prove impact.”

Source: RevenueBase Database · checked Sep 6, 2026
13Indirect evidenceSan Jose, CA, United StatesHQ checked Sep 6, 2026201-500523 contacts →

Indirect evidence

“The Pipeline Group helps B2B tech companies scale pipeline fast through our SDR-as-a-Service model.”

Source: RevenueBase Database · checked Sep 6, 2026
14Partial evidenceSan Jose, CA, United StatesHQ checked Sep 6, 2026201-500482 contacts →

Partial evidence

“InfoAnalytica is a B2B sales acceleration partner for mid-market and enterprise companies.”

Source: RevenueBase Database · checked Sep 6, 2026
15Indirect evidenceSunnyvale, CA, United StatesHQ checked Sep 6, 202651-200480 contacts →

Indirect evidence

“At SMARTe, we understand the challenges faced by revenue-generating teams.”

Source: RevenueBase Database · checked Sep 6, 2026
16Indirect evidenceDenver, CO, United StatesHQ checked Sep 6, 202651-200455 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 6, 2026
17Partial evidenceWest Hollywood, CA, United StatesHQ checked Sep 6, 2026201-500368 contacts →

Partial evidence

“Invoca is the revenue execution and platform leader that helps marketing, commerce, and contact center teams turn every conversation into revenue.”

Source: RevenueBase Database · checked Sep 6, 2026
18Strong evidenceAtlanta, GA, United StatesHQ checked Sep 6, 2026201-500332 contacts →

Strong evidence

“CallRail is the lead engagement platform that makes it easy for businesses to attract more leads, convert more customers, and optimize their marketing.”

Source: RevenueBase Database · checked Sep 6, 2026
19Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 6, 202651-200318 contacts →

Indirect evidence

“Nooks is the Agent Workspace for intelligent outbound.”

Source: RevenueBase Database · checked Sep 6, 2026
20Indirect evidenceRedwood City, CA, United StatesHQ checked Sep 6, 2026201-500297 contacts →

Indirect evidence

“Aviso delivers Agentic AI that turns insights into autonomous actions, giving GTM teams precision, speed, and control to drive predictable growth at scale.”

Source: RevenueBase Database · checked Sep 6, 2026
21Indirect evidenceMission, KS, United StatesHQ checked Sep 6, 2026501-1,000292 contacts →

Indirect evidence

“VinSolutions is automotive CRM software designed to help dealerships turn shopper behavior into action-and results.”

Source: RevenueBase Database · checked Sep 6, 2026
22Strong evidenceHenderson, NV, United StatesHQ checked Sep 6, 2026n/a260 contacts →

Strong evidence

“Best-in-class sales & marketing automation platform and marketplace for digital business owners and online marketers”

Source: RevenueBase Database · checked Sep 6, 2026
23Indirect evidenceWaltham, MA, United StatesHQ checked Sep 6, 2026201-500249 contacts →

Indirect evidence

“Bigtincan is now officially part of Showpad.”

Source: RevenueBase Database · checked Sep 6, 2026
24Strong evidenceLos Angeles, CA, United StatesHQ checked Sep 6, 2026201-500241 contacts →

Strong evidence

“Convoso is an AI-powered contact center platform built for revenue teams and customer engagement organizations expanding into outbound growth.”

Source: RevenueBase Database · checked Sep 6, 2026
25Partial evidenceChicago, IL, United StatesHQ checked Sep 6, 2026201-500232 contacts →

Partial evidence

“Tacton is a leading SaaS company redefining buyer engagement for manufacturers of complex products.”

Source: RevenueBase Database · checked Sep 6, 2026

Showing 25 of 1,479 sales engagement platform developers based in the United States

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Sales engagement platform developers based in the United States at a glance

As of Sep 6, 2026
33.3%Verified-email coverage
26.0%Mobile-number coverage
26.1Average contacts per company
1-10Median size (employees)
9.9%Largest-city concentration · San Francisco
Sep 6, 2026Page data refreshed

Companies by employee count

1-10
800
11-50
493
51-200
136
201-500
28
501-1,000
11
1,001-5,000
10
10001+
1

Freshness & accuracy

How recently the business emails on this list were verified

Email last verified

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among sales engagement platform developers, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in the United States whose own description of what they do matches “sales engagement platform developers”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names sales engagement platform developers), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among sales engagement platform developers, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 12,884 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 6, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names sales engagement platform developers, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many sales engagement platform developers are there based in the United States?

RevenueBase identified 1,479 sales engagement platform developers headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Klaviyo, headquartered in Boston, tops this list with the largest team on record.

Which city has the most sales engagement platform developers?

San Francisco leads with 146 headquartered companies, followed by New York (92) and Los Angeles (46).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 12,884 verified decision-maker contacts tracked across these 1,479 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 6, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.