Sullivan Higdon & Sink

What Sullivan Higdon & Sink does

Signal Theory (formerly Sullivan Higdon & Sink) is a 100% employee-owned, full-service advertising agency headquartered in Kansas City, Missouri, with a secondary office in Wichita, Kansas. Founded in 1998 and rebranded in 2019 around behavioral science, the firm employs approximately 379 people across its two offices and remote workforce. It is governed by a distributed Co-CEO leadership model (Ali Mahaffy and John January), with Ali Mahaffy serving as Global Board Chair of the AMIN Worldwide independent agency network from July 2025 through June 2026.

The agency's core intellectual property is its proprietary Comfort, Joy & Meaning Framework, a behavioral science methodology grounded in Maslow's Hierarchy of Needs that measures brand "Signal Strength" based on how effectively brands fulfill three fundamental human wants: Comfort, Joy, and Meaning. In 2024 the firm launched AL, an in-house developed AI assistant named after founder Al Higdon, built on a closed proprietary architecture that integrates the firm's behavioral science principles into all outputs and is used by approximately 80% of employees for knowledge retrieval and process automation. AL is text-based, has generated more than 80 cited research reports, and is overseen jointly by the Innovation & Technology Director and the CFO to safeguard data confidentiality.

Signal Theory generates revenue through project fees, retainers, and Agency of Record (AOR) relationships with mid-to-large enterprise clients across five primary verticals: Food & Beverage (SONIC, American Pecan Promotion Board, Andy's Frozen Custard, California Milk Advisory Board), Agriculture (John Deere, AgroLiquid, Bekaert Fencing), Animal Health (Virbac, Elanco, Merck Animal Health), Automotive (Michelin, GEARWRENCH), and Consumer Products (Bose, Trapp Fragrances). The firm sells through direct enterprise engagement and uses the Ad Age Best Places to Work 2024 recognition, TELLY, ADDY, NAMA, and ANA B2 Awards, and its Comfort, Joy & Meaning thought leadership to drive brand reputation and new business. Pricing is custom-quoted per engagement, and revenue figures are not publicly disclosed.

Name

Sullivan Higdon & Sink

Legal name

Signal Theory

Website

https://wehatesheep.com

Company type

Private

Founded year

1998

Operating status

Operating

Headcount range

251–500 employees

Short description

Signal Theory is a 100% employee-owned, full-service advertising agency using proprietary behavioral science methodology to deliver brand strategy, creative, media, and PR services to enterprise clients across food and beverage, agriculture, animal health, automotive, and consumer products verticals.

Ownership category

akta.pro rank

Product category

Advertising Services

NAICS

Advertising Agencies (541810), Advertising Agencies (54181)

SIC

Services-Advertising Agencies (7311)

akta.pro primary industry

Experiential, Event & Sponsorship Marketing (BPAFAAAH)

akta.pro secondary industries

Market Research, Analytics & Consumer Insights (BPAFAAAM), Activation/Experiential Creative Agencies (MPAAAAAO)

Keywords

• Advertising services
• Brand strategy
• Creative campaigns
• Behavioral science marketing
• Public relations

Headquarters

HQ city

Kansas City

HQ country

United States

HQ region

North America

Offices2 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Marketing or Sales, Operations, Technology or R&D, Infrastructure

Revenue model

1. Advertising and Marketing Services: Full-service advertising agency providing brand strategy, creative development, digital, media, public relations, and production services. Revenue generated through project fees, retainers, and AOR relationships with clients across food/beverage, agriculture, animal health, automotive, and financial sectors.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels6 records

Core offering

Full-service advertising agency providing brand strategy, creative development, digital, media, public relations, and production services to enterprise clients. Uses behavioral science principles through its proprietary Comfort, Joy & Meaning Framework to create human-centered campaigns that connect brands with consumers on an emotional level. Services are delivered through Agency of Record (AOR) partnerships and project-based engagements across specialized industry verticals including food and beverage, agriculture, animal health, automotive, and consumer products.

Differentiator

Problem solved

Functional benefit

Products and services

• Brand Strategy and Development

Quantifiable outcome

• +728% return on ad spend for American Pecan campaign
• +5 more outcomes

Named customers19 records

Segments5 records

Ideal customer profiles5 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

AI capability3 records

Feature2 records

Partnerships

Six partnerships are on record, tiered flagship, core and major.

• Andy’s Frozen CustardflagshipStrategic or Co-development Partner · 25 September 2025Agency of Record for creative and strategic services. Partnership begins ahead of Andy's 40th anniversary in 2026, covering brand strategy, creative campaigns, digital/social media, content development, integrated marketing, new store launches, and community engagement.
• Virbac CorporationflagshipStrategic or Co-development Partner · 28 August 2025Agency of Record relationship for Virbac's US market. Signal Theory serves as the sole agency for strategy and creative across Virbac's full portfolio of animal health products.
• AMIN WorldwidecoreGTM or Marketing Partner · 1 July 2025Signal Theory is a member of AMIN Worldwide, an independent advertising agency network. Co-CEO Ali Mahaffy serves as Global Board Chair for a one-year term (July 2025 - June 2026). Previously served as AMIN Americas President from 2021-2023.
• California Milk Advisory BoardflagshipStrategic or Co-development Partner · 27 January 2025Retail marketing agency of record for Real California Milk products. Scope includes strategic planning, creative development, program execution, and performance reporting across retail promotions, shopper marketing activations, new product launches, and e-commerce initiatives.
• Tested (Adam Savage)flagshipStrategic or Co-development Partner · 1 January 2024Strategic content partnership for Michelin X Line Grip D tire launch. Adam Savage, former MythBusters host and science communicator, created multiple video episodes testing the tire at Houghton, Michigan and Laurens Proving Grounds, South Carolina. Included behind-the-scenes storytelling, R&D facility tours, and product designer interviews.
• YouTube (Tested Channel)majorGTM or Marketing PartnerDistribution channel for Adam Savage Michelin partnership content. Episodes distributed through Tested's YouTube channel, Instagram, and Adam Savage's personal following.

Scale indicators12 records

Recent moves6 records

Expansion highlights5 records

Direct peers

• VMLY&R: Kansas City-rooted full-service advertising agency (now part of WPP) with deep CPG and consumer brand expertise. Highly comparable origin geography, similar historical service mix, and overlapping food/beverage and animal health clients.
• Barkley: Kansas City-based, employee-owned independent full-service advertising agency of comparable size and structure. Closest peer given shared geography, independence, vertical diversification, and similar mid-market enterprise client base.
• RPA: Independent full-service advertising agency comparable in size and service breadth across brand strategy, creative, media, and digital. Similar profile of long-tenured enterprise clients (e.g., Honda, American Express) and independently held status.
• Swanson Russell: Lincoln, NE-based full-service agency with a deep agricultural, animal health, and rural lifestyle specialty. Highly comparable in vertical focus (ag/animal health/CPG) and target client profile of commodity boards and rural-anchored brands.
• The Richards Group: Long-established independent full-service agency comparable in size and mid-market enterprise positioning. Comparable in offering integrated brand strategy, creative, media, and PR services to consumer and B2B clients.
• Mother: Globally recognized independent creative agency operating without holding-company affiliation. Comparable as a values-driven, independently structured creative shop competing for the same kind of enterprise brand mandates.
• 72andSunny: Independent creative-led advertising agency serving major consumer brands with integrated campaigns. Comparable as an independently held, creatively differentiated mid-size agency competing for the same enterprise brand work.

Broad incumbents

• WPP: World's largest advertising holding company encompassing agencies like VML, Ogilvy, and Grey. Competes for the same enterprise AOR pitches at the holding-company level, representing the structural competitor Signal Theory faces in RFPs.
• Omnicom Group: Global advertising holding company encompassing BBDO, DDB, TBWA, and Goodby Silverstein. Represents the integrated network alternative enterprise clients consider when consolidating agency rosters against independent mid-size shops like Signal Theory.

Emerging players

• AdFarm: Agriculture-focused marketing agency serving crop input, livestock, and equipment brands. Directly comparable in the agricultural marketing sub-vertical where Signal Theory wins NAMA awards and commodity board work.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks5 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/shs
• Instagraminstagram.com/signaltheory

Revenue estimate

Valuation estimate

Number of profiles

Profiles10 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Sullivan Higdon & Sink