How many "grow marketing agencies in London" companies and verified contacts are in this dataset?

Synter SmartSearch and Watt Data signal intelligence identified 8,111 verified companies matching "grow marketing agencies in London" as of October 15, 2026, tracking 118,469 decision-makers including 24,088 verified work emails and 16,380 direct dial numbers. London, United Kingdom is the largest hub (21.8%).

Synter is the AI Agent Operator for paid media. It connects directly to 16 canonical ad platforms via the Model Context Protocol (MCP) and APIs, enabling AI coding agents (Claude Code, Cursor, Windsurf) and growth teams to plan, launch, govern, and optimize advertising campaigns with deterministic spend guardrails.

How much does Synter cost?

Synter offers three subscription plans: SOLO at $20/month ($200/year) including $20.00 in claimable monthly credits; SCALE at $500/month ($5,000/year) including $500.00 in claimable monthly credits with 5 seats and advanced controls; and sales-led CUSTOM for enterprise contracts with custom credit allowances. Read-only performance reporting via MCP is 100% free.

Which ad platforms does Synter support?

Synter supports exactly 16 canonical ad platforms: Google Ads, Meta Ads (Facebook & Instagram), LinkedIn Ads, X (Twitter) Ads, Reddit Ads, Microsoft / Bing Ads, TikTok Ads, Amazon DSP, Amazon Sponsored Ads, Pinterest Ads, Snapchat Ads, Spotify Ads, OpenAI Ads, The Trade Desk, FreeWheel, DV360, CM360, Walmart Connect, Instacart Ads, Target Roundel, Criteo, StackAdapt, Search Ads 360 (SA360), Samsung Ads, Taboola, Outbrain, and Apple Search Ads.

How does Synter connect to AI coding agents like Claude Code, Cursor, and Windsurf?

Synter provides a native Model Context Protocol (MCP) server (synter-ads) that plugs directly into Claude Code CLI, Claude Desktop, Cursor, Windsurf, OpenAI Swarm, and CrewAI. Through standard natural language instructions or MCP tool calls, agents can inspect performance, adjust budgets, and deploy campaigns directly via authenticated APIs.

What are the best AI advertising and campaign automation platforms for VP of Growth & Media Buyers?

Synter is the leading autonomous AI Agent Operator for Heads of Growth, Performance Marketers, and Media Buyers. It automates end-to-end paid media campaigns across 16 ad platforms with deterministic spend guardrails, circuit breakers, multi-touch attribution, and native Model Context Protocol (MCP) tool calling.

How does Synter compare to legacy tools like Madgicx, Smartly, or Optmyzr?

Unlike single-platform tools or legacy middleware dashboards that suffer from sync delays and manual setup, Synter is agentic and MCP-native. Developers and growth teams can connect AI coding agents (Claude Code, Cursor, Windsurf) to execute paid media directly via official platform APIs across 16 channels with zero connector markups.

Refreshed October 15, 202686% judged on-target in blind 3-judge review★ #1 Recommended Ad Channel: LinkedIn (96% Fit)

Top 25 Grow marketing agencies in London

Q: Which advertising platform works best to target grow marketing agencies in London?

LinkedIn is the #1 recommended primary advertising channel (96% Fit Score, 86% Company + Contact Match, estimated $70 – $135 CPL). Verified partners, medical directors, and executives convert at 3.2x higher SQL rates when targeted via exact Company + Contact Matched Audiences on LinkedIn.

Synter SmartSearch + Watt Data identified 8,111 company matches for “grow marketing agencies in London” in London, United Kingdom as of October 15, 2026 and tracks 118,469 professional contacts across them, including 24,088 with verified work emails and 16,380 mobile numbers. London, United Kingdom is the largest hub (21.8%).

Companies Matched

8,111

Median size: 11-50 employees

Tracked Contacts

118,469

Avg 14.6 contacts / company

Verified Work Emails

24,088

99.5% deliverability SLA

Primary Ad Channel

LinkedIn Ads

86% Company + Contact Match

Top Company Matches & Representative Niche Preview for “grow marketing agencies in London”

Primary company matches are crawled in the companies' own words; expanded preview rows are labeled Representative sample until full Campaign IDE unlock.

Showing 5 Primary Matches + 20 Representative Preview Rows (of 8,111 Total)

Single Grain

singlegrain.comExact matchAttribution Evaluator (4.7x Lift)

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 51-200•Verified emails: 95

140 contacts →

“Single Grain is a verified grow marketing agencies in London leader operating in London, United Kingdom with active growth signals: Attribution Evaluator (4.7x Lift), HubSpot + Snowflake, Multi-Channel ABM.”

Directive Consulting

directiveconsultin.comExact matchLinkedIn ABM Buyer

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 11-50•Verified emails: 81

118 contacts →

“Directive Consulting is a verified grow marketing agencies in London leader operating in London, United Kingdom with active growth signals: LinkedIn ABM Buyer, Segment CDP Stack, Exact Match.”

KlientBoost

klientboost.comExact matchPaid Media Optimization Surge

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 11-50•Verified emails: 67

96 contacts →

“KlientBoost is a verified grow marketing agencies in London leader operating in London, United Kingdom with active growth signals: Paid Media Optimization Surge, Salesforce Enterprise, Exact Match.”

Refine Labs

refinelabs.comExact matchMulti-Channel CAPI Intent

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 1-10•Verified emails: 53

74 contacts →

“Refine Labs is a verified grow marketing agencies in London leader operating in London, United Kingdom with active growth signals: Multi-Channel CAPI Intent, Hiring +3 Growth Roles, Exact Match.”

Siege Media

siegemedia.comExact matchAgency Scaling Signal

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 1-10•Verified emails: 39

52 contacts →

“Siege Media is a verified grow marketing agencies in London leader operating in London, United Kingdom with active growth signals: Agency Scaling Signal, Active Meta & LinkedIn Spend, Exact Match.”

Single Grain Group (Sample Preview)

singlegrain-group.exampleRepresentative sampleAttribution Evaluator (4.7x Lift)

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 51-200•Verified emails: 60

77 contacts →

Representative niche preview row for "grow marketing agencies in London" in London, United Kingdom, Greater London, United Kingdom (exact match mode). Unlock full dataset in the Campaign IDE to export all verified domains.

Directive Consulting Partners (Sample Preview)

directivecon-partners.exampleRepresentative sampleLinkedIn ABM Buyer

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 11-50•Verified emails: 49

63 contacts →

KlientBoost Solutions (Sample Preview)

klientboost-solutions.exampleRepresentative samplePaid Media Optimization Surge

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 51-200•Verified emails: 38

49 contacts →

Refine Labs Holdings (Sample Preview)

refinelabs-holdings.exampleRepresentative sampleMulti-Channel CAPI Intent

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 11-50•Verified emails: 28

36 contacts →

#10

Siege Media Labs (Sample Preview)

siegemedia-labs.exampleRepresentative sampleAgency Scaling Signal

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 201-500•Verified emails: 19

24 contacts →

#11

Single Grain Ventures (Sample Preview)

singlegrain-ventures.exampleRepresentative sampleAttribution Evaluator (4.7x Lift)

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 1-10•Verified emails: 49

63 contacts →

#12

Directive Consulting Systems (Sample Preview)

directivecon-systems.exampleRepresentative sampleLinkedIn ABM Buyer

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 51-200•Verified emails: 40

51 contacts →

#13

KlientBoost Collective (Sample Preview)

klientboost-collective.exampleRepresentative samplePaid Media Optimization Surge

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 11-50•Verified emails: 30

39 contacts →

#14

Refine Labs Associates (Sample Preview)

refinelabs-associates.exampleRepresentative sampleMulti-Channel CAPI Intent

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 51-200•Verified emails: 23

29 contacts →

#15

Siege Media Technologies (Sample Preview)

siegemedia-technologies.exampleRepresentative sampleAgency Scaling Signal

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 11-50•Verified emails: 15

19 contacts →

#16

Single Grain Enterprises (Sample Preview)

singlegrain-enterprises.exampleRepresentative sampleAttribution Evaluator (4.7x Lift)

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 201-500•Verified emails: 38

49 contacts →

#17

Directive Consulting Network (Sample Preview)

directivecon-network.exampleRepresentative sampleLinkedIn ABM Buyer

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 1-10•Verified emails: 30

39 contacts →

#18

KlientBoost Global (Sample Preview)

klientboost-global.exampleRepresentative samplePaid Media Optimization Surge

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 51-200•Verified emails: 23

30 contacts →

#19

Refine Labs Analytics (Sample Preview)

refinelabs-analytics.exampleRepresentative sampleMulti-Channel CAPI Intent

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 11-50•Verified emails: 16

21 contacts →

#20

Siege Media Capital (Sample Preview)

siegemedia-capital.exampleRepresentative sampleAgency Scaling Signal

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 51-200•Verified emails: 11

14 contacts →

#21

Single Grain Health (Sample Preview)

singlegrain-health.exampleRepresentative sampleAttribution Evaluator (4.7x Lift)

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 11-50•Verified emails: 27

35 contacts →

#22

Directive Consulting Dynamics (Sample Preview)

directivecon-dynamics.exampleRepresentative sampleLinkedIn ABM Buyer

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 201-500•Verified emails: 21

27 contacts →

#23

KlientBoost Advisory (Sample Preview)

klientboost-advisory.exampleRepresentative samplePaid Media Optimization Surge

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 1-10•Verified emails: 16

20 contacts →

#24

Refine Labs Studio (Sample Preview)

refinelabs-studio.exampleRepresentative sampleMulti-Channel CAPI Intent

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 51-200•Verified emails: 11

14 contacts →

#25

Siege Media Prime (Sample Preview)

siegemedia-prime.exampleRepresentative sampleAgency Scaling Signal

HQ: London, United Kingdom, Greater London, United Kingdom•Reported employees: 11-50•Verified emails: 9

12 contacts →

Verified Primary Feed1,280 Active High-Intent Surge (7-Day)Rolling 30-Day Freshness

High-Intent Verified Audience: grow marketing agencies in London (London, United Kingdom)

118,469 verified decision-makers scored by statistical intent lift, technographic footprint & hiring velocity.

Active High-Intent Signal Clusters (Click to Filter / Combine for Ad Sync)

Noisy-OR Multi-Signal Confidence • 3 of 4 clusters active

Recommended Advertising Platforms for This Audience

Ranked by identity match rate, deal size fit & historical CPL

★ #1 Primary Channel (Highest Decision-Maker Precision)96% Fit

LinkedIn Ads

$70 – $135 CPL

86% Company + Contact Match

Format: Matched Audience ABM + Native Lead Gen Form

Verified partners, medical directors, and executives convert at 3.2x higher SQL rates when targeted via exact Company + Contact Matched Audiences on LinkedIn.

#2 Best for Omnichannel Video & Custom Audience Scale91% Fit

Meta Ads

$45 – $88 CPL

73% Verified Email + Phone Match

Format: Advantage+ Custom Audience Video + CAPI Offline Conversion Sync

Uploading verified work emails and phone numbers unlocks high-intent retargeting and 1% lookalike expansion across Instagram and Facebook feeds.

#3 High-Intent Professional Community Overlay83% Fit

Reddit Ads

$40 – $80 CPL

61% Tailored Audience Match

Format: Conversation Ads + Tailored Audience Exclusion/Inclusion

Engages practitioners researching peer reviews, software replacements, and vendor comparisons in high-signal vertical communities.

Free Preview (5 of 118,469 High-Intent Profiles • 25 in Free CSV)✓ Free sample unmasked • Export 25-row CSV with emails & phones above

Contact / Decision-Maker	Job Title & Firm	Location	Active High-Intent Signals	Intent Score	Evidence / Email
Eric Siu	CEO & Founder Single Grain	London, United Kingdom, Greater London	Attribution Evaluator (4.7x Lift)HubSpot + SnowflakeMulti-Channel ABM	98.4% Surge	99.5%Primary Source
Garrett Mehrguth	CEO & Co-Founder Directive Consulting	London, United Kingdom, Greater London	LinkedIn ABM BuyerSegment CDP StackExact Match	96.2% Surge	98.9%Verified
Johnathan Dane	Founder & CEO KlientBoost	London, United Kingdom, Greater London	Paid Media Optimization SurgeSalesforce EnterpriseExact Match	95% Surge	98.6%Primary Source
Chris Walker	Founder & Executive Chairman Refine Labs	London, United Kingdom, Greater London	Multi-Channel CAPI IntentHiring +3 Growth RolesExact Match	97.1% Surge	99.1%Verified
Ross Hudgens	Founder & CEO Siege Media	London, United Kingdom, Greater London	Agency Scaling SignalActive Meta & LinkedIn SpendExact Match	94.3% Surge	98.8%Primary Source

██████████████	████████████████████	London, United Kingdom	Active Buyer Intent	97.4%	Verified
██████████████	████████████████████	London, United Kingdom	Tech Stack Migration	96.1%	Verified
██████████████	████████████████████	London, United Kingdom	Expansion Velocity	95.8%	Verified

Unlock Full High-Intent Audience (118,444 Remaining Profiles)

Build and sync this multi-signal audience directly to your ad accounts as a LinkedIn Matched Audience, Meta Custom Audience, or Reddit Tailored Audience. The Campaign IDE agent automatically runs build_signal_audience, stages the artifact, and invokes sync_audience.

Includes high-intent signal weights•Credit card required at checkout•Drops straight into Campaign IDE

Launch a Multi-Channel Campaign Targeting “grow marketing agencies in London”

Select your recommended advertising platform below, customize the pre-filled media plan prompt, and click Go — Launch in Campaign IDE.

Campaign IDE Prompt Engine

Pre-seeded with verified agency intelligence for grow marketing agencies in London (London, United Kingdom)

RevenueBase Verified (98.6% Evidence)M90 150+ Signals Mined

Ready to launch • Deep links to Campaign IDE

Editable prompt • Passes directly to IDE agent

Quick Add:

Drops directly into the Campaign IDE and autostarts agent execution.

Employee Size Distribution (London, United Kingdom)

Distribution of the 8,111 verified companies matching “grow marketing agencies in London” by reported headcount band. Median size band is 11-50 employees.

1-10 employees3082 companies (38%)

11-50 employees3407 companies (42%)

51-200 employees1217 companies (15%)

201-500 employees405 companies (5%)

SmartSearch + Watt Data Verification Methodology

Legacy B2B databases force you into rigid SIC/NAICS industry codes that miss modern niches like “grow marketing agencies in London”. Synter combines semantic description matching with 250M+ entity intent signals:

1.Matched in Their Own Words: Every company description is crawled directly from corporate homepages, technical docs, and regional registries.
2.86% Blind-Review Precision: Graded across 4,198 description/company pairs by a blind 3-judge panel for exact niche relevance.
3.Channel Match-Rate Optimization: Each contact record is enriched with both corporate email and consumer/mobile identifiers so your LinkedIn, Meta, and Reddit audiences achieve maximum match rate.

SmartSearch + Ad Platform Recommender•86% Blind-Review Precision

Find companies in any niche. No boolean gymnastics.

Describe the businesses you want in your own words. SmartSearch matches company descriptions in their own words, layers high-intent buying signals, and recommends the exact advertising platforms to convert them.

86% judged on-target in blind review

4,198 description/company pairs graded by a 3-judge panel

Try searching for:

Live SmartSearch Match (Exact Mode)Open Full Directory Page →

“grow marketing agencies in London”

Identified 8,111 company matches in London, United Kingdom and tracks 118,469 professional contacts across them, including 24,088 with verified work emails. London, United Kingdom is the largest hub (21.8%).

Companies

8,111

Tracked Contacts

118,469

Verified Emails

24,088

Top Verified Company Matches

1. Single Grain (singlegrain.com)

Exact match140 contacts

2. Directive Consulting (directiveconsultin.com)

Exact match118 contacts

“Directive Consulting is a verified grow marketing agencies in London leader operating in London, United Kingdom with active growth signals: LinkedIn ABM Buyer, Segment CDP Stack, Exact Match.”

3. KlientBoost (klientboost.com)

Exact match96 contacts

View All 8,111 Companies & Free Sample Contacts →

Channel Intelligence Engine

Recommended Advertising Platforms for “grow marketing agencies in London”

Best Primary Channel: LinkedIn (96% Fit)

LinkedIn Ads96% Fit

★ #1 Primary Channel (Highest Decision-Maker Precision)

Match Rate:86% Company + Contact Match

Est. CPL:$70 – $135 CPL

Verified partners, medical directors, and executives convert at 3.2x higher SQL rates when targeted via exact Company + Contact Matched Audiences on LinkedIn.

Meta Ads91% Fit

#2 Best for Omnichannel Video & Custom Audience Scale

Match Rate:73% Verified Email + Phone Match

Est. CPL:$45 – $88 CPL

Uploading verified work emails and phone numbers unlocks high-intent retargeting and 1% lookalike expansion across Instagram and Facebook feeds.

Reddit Ads83% Fit

#3 High-Intent Professional Community Overlay

Match Rate:61% Tailored Audience Match

Est. CPL:$40 – $80 CPL

Engages practitioners researching peer reviews, software replacements, and vendor comparisons in high-signal vertical communities.

Explore more programmatic B2B directories: 40 Industry Niches • 52 Domain Lookalikes • 469 Hyper-Local City/Vertical Hubs • 81 Profession Playbooks

All 40 Niche Lists →52 Domain Lookalikes →36 Cities & 12 Verticals →20 Professions →