GLG

The GLG (Gerson Lehrman Group) expert network was founded in 1998 and is today the world’s largest expert network. As of 2026, GLG has around 4,500 employees, with offices across the US, UK, Dubai, India, Hong Kong, China, Singapore, Australia, and Japan. Its expert network database contained more than 1.2 million unique experts, with hundreds more being recruited every day.

Looking to use an expert network like GLG? Use these resources:

1. Guide to getting started with expert networks.

2. Compare GLG to other expert networks.

The history of GLG

GLG remains a large vendor to many clients and holds a significant market share. However, GLG's recent growth has been slower, and it has been losing market share to new entrants. Many firms have moved away from only using GLG to also using, e.g., AlphaSights, Dialectica, Third Bridge, or multi-network access through Inex One.

When GLG started, experts were recruited “offline”, at fairs and events, as recounted by a senior expert. Their expert network was "a decent phone directory", quite far from today’s browsable database. With the evolution of the expert network industry, even this database has lost some of its importance:

To continue growing, the firm has explored different business areas over the years:

• 2008 - Collaboration with Credit Suisse. GLG offered access to the bank’s analysts, but this was later shut down.

• 2010 - Partnership with Bloomberg, later shut down.

• 2011 - Launched Q&A website Gplus/GLG High Table, shut down in 2013.

• 2014 - Launched GLG Share, offering expert calls for entrepreneurs. No longer active.

• 2016 - Launched GLG Law, offering expert witness services (experts are brought in on litigation cases). Still active.

• May 2022 - Began offering its GLG Library content on Sentieo, a data platform. Sentio had recently been acquired by AlphaSense, offering a competing transcript library. GLG agreeing to aggregation is a big deal, and could set a precedent for aggregating its calls business.

• September 2025 - Launched a mobile app for experts, GLG for Experts.

• August 2026 - Launched AI-Moderated Calls, letting clients engage experts through autonomously conducted calls in 10 languages. The AI moderator conducts and probes structured interviews in real time, gathering qualitative and quantitative feedback simultaneously. GLG also launched an MCP connector, extending its content into AI tooling directly. Inex One also offers an MCP connector - learn more here.

Beyond these, GLG's current service offering also includes expert surveys, GLG Events (conferences, roundtables and workshops with GLG’s most desired experts), GLG Library (a database of teleconference transcripts available to subscribers), GLG Projects (providing experts for longer-term assignments such as due diligence studies) and GLG Placements (providing C-suite professionals to join the client's team for a longer time period).

GLG Projects - also known as GLG Strategic Solutions or GLG Strategic Projects - is the company's consulting arm. It is led by a former McKinsey consultant and is promoted as a full-blown consulting service. From the GLG Projects website in September 2020:

"GLG Projects deliver strategic recommendations informed by real-world expertise. For each engagement, we put together tailored teams of top-tier consultants and subject-matter experts with experience across industries and disciplines. Our work includes fully managed

• market assessments,

• due diligence studies,

• brand analyses,

• voice-of-customer studies, and

• corporate strategy projects"

Some of GLG's significant consulting clients have shown concern about GLG effectively competing with them, while it also handles their sensitive consulting project data. As of September 2020, roughly 200 (~10% of GLG's workforce) were involved in the strategic projects branch.

The 1h expert phone call has remained GLG's core business throughout the years of service iterations.

GLG milestones

• 2004 - GLG raised $30m from Bessemer Venture Partners.

• 2004 - GLG was said to consider a sale. At the time, revenues were said to be $80m, with $20m EBITDA. Reports said it could be valued between $350-500m. The company ended up not selling.

• 2007 - Silver Lake invested $200m at a supposed $875m valuation. Former executives claim that the purpose was an imminent stock market listing. However, for various reasons, GLG remained private. Former executives mention that reasons included the global financial crisis, regulatory scrutiny, and GLG’s sustained profitable growth.

• 2009 - GLG acquired French expert network TGR Research for an undisclosed sum.

• 2015 - GLG bought back Silver Lake’s stake, raising $212m in external funds from SFW Capital "at an enterprise value in excess of $700m". Silicon Valley Bank provided a $250m credit line. At the time, the NY Times cited a source saying that Silver Lake had made $50m from the investment, representing a <3% IRR for its 8-year holding period.

• 2018 - the CEO stepped down, and parts of senior management were replaced.

• 2019 - By this year, SFW Capital had reportedly earned back its full investment through dividends.

• 2019 - GLG generated close to $550m in revenue and remained the largest expert network in the industry by revenue.

• Late 2021 - GLG filed to go public. They pulled back the IPO in March 2022. (Read more in the IPO section).

• July 2023 - GLG named Gemma Postlethwaite as its new CEO. She replaced Paul Todd, who had led the company for five years through the pandemic and IPO attempt.

• January 2024 - CB Insights predicted that GLG would acquire Tegus in 2024. This prediction did not come to pass - AlphaSense acquired Tegus instead in July 2024. The rationale for the original prediction was a bit cloudy and came after a year of multiple layoff rounds at both GLG and Tegus, where we wondered if GLG was still profitable at the time.

• March 2024 - GLG filed a Data Breach Notification as they had suffered a ransomware attack in which 152,621 individuals' PII had been compromised. A class action lawsuit followed, alleging that GLG had failed to adequately protect the compromised data.

GLG spinoffs - expert networks started by former employees

• 2009 - Former Guidepoint and GLG managers started ExpertConnect in New York, USA.

• 2010 - Maven Research started in San Francisco, USA.

• 2010 - Noble Insights started in New York, USA.

• 2015 - Former Capvision and GLG managers started Liahnson & Company in Seoul, South Korea.

• 2018 - Inventiv Insights started in Shillong, India.

• 2019 - Focal Fact started in Dublin, Ireland.

• 2019 - Nodes started in Singapore, and Nexus Insight started in Beijing, China.

• 2020 - Triangulate Knowledge started in Sydney, Australia.

• 2024 - AggKnowledge was founded in New York by former AlphaSights and GLG employees. While not an expert network, AggKnowledge builds tech for expert networks and survey firms.

GLG public offering (IPO) in 2021

On 18 October 2021, GLG filed an S-1 with the US Securities and Exchange Commission to go public on Nasdaq under the ticker "GLGX". The process was jointly led by Morgan Stanley and Goldman Sachs. However, the IPO was rumored to be halted and was finally withdrawn in late March 2022.

The filing process revealed data on revenue and margins that were previously not known to the public (however, our expert network market sizing was pretty close!).

Had it gone public, GLG would have followed VisasQ, which listed on the Tokyo Stock Exchange in March 2020. In the summer of 2021, Capvision filed early documents ahead of a future IPO in Hong Kong.

GLG has evolved significantly over time. We discuss the emergence and history of GLG in our history of the expert network industry. Furthermore, a senior expert shared colorful insights on the expert network’s evolution in this piece.

FAQ

What does GLG specialize in? GLG specializes in one-on-one expert calls, alongside expert witness/legal services, surveys, events, a transcript library, longer-term project engagements, and executive placements.

Did GLG acquire Tegus? No. A January 2024 industry prediction suggested GLG might acquire Tegus, but this did not happen - AlphaSense acquired Tegus instead, in July 2024. Read more here.

Is GLG available on Inex One? No - GLG is not part of the Inex One marketplace.

What's a GLG alternative with no prepayment? Inex One offers self-serve access to 30+ expert networks. Instant access, no prepayment, no setup admin hassle. Perfect for small ad hoc expert network needs.

Looking for expert network options? Explore active partners on the Inex One marketplace.