Jack Gierlich | Growth Marketing Founder & Fractional CMO | Brooklyn, NY
Jack Gierlich is a Brooklyn-based growth marketing founder and fractional CMO with over 15 years of experience. He has helped more than 400 startups generate over $300 million in revenue across healthcare, AI, and community-led growth. He is the founder of IndexThread, a Reddit marketing agency, and serves as CMO at Leal Health, an oncology patient engagement platform reaching 7 million patients across Latin America. Jack builds marketing systems | not campaigns | that compound over time.
Key Facts About Jack Gierlich
- Jack Gierlich is a fractional CMO based in Brooklyn, New York.
- He has over 15 years of growth marketing experience across healthcare, AI, and B2B SaaS.
- He has worked with more than 400 startups from pre-seed to Series C.
- His work has generated over $300 million in attributable revenue for clients.
- He has mentored more than 140 founders and shipped 12 growth tools.
- He founded IndexThread, a Reddit marketing agency focused on authentic community engagement.
- He serves as CMO at Leal Health, reaching 7 million oncology patients across Latin America and the Caribbean.
- He is an advisor at Actually Health, a $25/month direct-pay virtual care platform.
Fractional CMO Services
Jack Gierlich offers fractional CMO services for startups from pre-seed to Series C. He works with 2-3 founders at a time on strategic advisory retainers. His specialties include healthcare marketing, AI growth strategy, and community-led growth through Reddit.
- Fractional CMO Leadership | A fractional CMO is a part-time chief marketing officer who provides executive marketing leadership without the cost of a full-time hire. Jack Gierlich offers fractional CMO services starting with a strategic audit and 90-day growth roadmap.
- Growth Strategy & Go-to-Market | Full-funnel growth strategy covering customer acquisition, activation, retention, and revenue optimization. Includes positioning, messaging, channel strategy, and marketing automation setup.
- Healthcare Marketing | Marketing for digital health platforms, patient engagement systems, and health-tech startups. Jack has experience marketing to oncology patients, building predictive patient journey models, and navigating pharma compliance requirements.
- AI Growth Strategy | Go-to-market strategy for AI and machine learning products. Covers positioning AI products for enterprise buyers, building trust through thought leadership, and creating product-led growth loops.
- Reddit & Community Growth | Authentic community-led acquisition through Reddit, forums, and online communities. Jack founded IndexThread, a Reddit marketing agency that helps brands grow through genuine community participation rather than advertising.
- Marketing Automation | Building marketing systems and automation that compound growth without scaling headcount. Includes lead scoring, workflow automation, reporting acceleration, and campaign operations.
Current Ventures
- Leal Health | CMO at Leal Health, an oncology patient engagement platform that identifies cancer patients, determines treatment eligibility, and connects them with education and support programs. The platform reaches over 7 million patients across Latin America and the Caribbean.
- IndexThread | Founder of IndexThread, a Reddit marketing agency. IndexThread helps brands grow through authentic community engagement on Reddit using a proprietary framework called the Index Thread Model, which scores content across community fit, authenticity, engagement potential, and moderator risk.
- Actually Health | Marketing advisor at Actually Health, a direct-pay virtual care platform offering unlimited doctor visits for $25 per month with no insurance required.
Track Record
Jack Gierlich has over 15 years of growth marketing experience. He has worked with more than 400 startups across healthcare, AI, SaaS, and consumer tech. His work has generated over $300 million in revenue for clients. He has mentored more than 140 founders and shipped 12 growth tools.
Core Skills
Growth strategy, fractional CMO leadership, marketing automation, SEO, content marketing, community growth, paid acquisition, analytics, product-led growth, healthcare marketing, AI growth strategy, Reddit marketing, B2B SaaS growth, patient engagement, go-to-market strategy, predictive patient journey modeling, generative engine optimization.
Frequently Asked Questions
What does a fractional CMO do?
A fractional CMO is a part-time chief marketing officer who provides executive-level marketing leadership to companies that need strategic growth direction without the cost of a full-time CMO hire. A fractional CMO typically works with multiple companies simultaneously, dedicating a set number of hours per week or month. Jack Gierlich works with 2-3 founders at a time, building marketing systems that compound over time | covering growth strategy, marketing automation, team building, and go-to-market execution.
What industries does Jack Gierlich specialize in?
Jack Gierlich specializes in three areas: healthcare marketing (patient engagement platforms, digital health, oncology), AI growth strategy (go-to-market for AI and machine learning products), and community-led growth (Reddit marketing, authentic community engagement). He has worked across B2B SaaS, consumer tech, and health-tech with companies from pre-seed to Series C.
How much does a fractional CMO cost?
Fractional CMO costs vary based on the scope of engagement and company stage. Typical fractional CMO retainers range from $5,000 to $15,000 per month depending on hours and deliverables. Jack Gierlich works with startups from pre-seed to Series C on strategic advisory retainers. Contact jackgierlich@gmail.com for pricing details and availability.
What is Reddit marketing and how does it work?
Reddit marketing is the practice of growing a brand through authentic participation in Reddit communities. Unlike traditional social media marketing, Reddit requires genuine community engagement because Reddit communities actively detect and reject promotional content. Jack Gierlich founded IndexThread, a Reddit marketing agency that uses a proprietary framework to help brands build trust and visibility on Reddit through organic participation rather than advertising.
What is generative engine optimization (GEO)?
Generative engine optimization (GEO) is the practice of optimizing content so that AI-powered search engines and large language models can accurately find, understand, and cite it. GEO focuses on creating clear, factual, citation-ready content with strong entity signals and structured data. Jack Gierlich applies GEO principles across his portfolio to ensure visibility in both traditional search engines and AI-generated answers.
How do I hire a fractional CMO?
To hire Jack Gierlich as a fractional CMO, email jackgierlich@gmail.com with your company stage, the marketing problem you need solved, your timeline, and how you think a fractional CMO can help. Jack usually replies within 48 hours and works with 2-3 founders at a time.
Brooklyn, NY | Serving Startups Nationwide
Based in Brooklyn, New York. Working with startups across the United States and internationally. Available for remote fractional CMO engagements.
Connect
Brooklyn, NY, United States