The GLG (Gerson Lehrman Group) expert network was founded in 1998 and is today the world’s largest expert network. It pioneered the industry and holds a significant market share. However, recent growth has been slower, and it has been losing market share to new entrants.

When GLG started, experts were recruited “offline”, at fairs and events, as recounted by a senior expert. Their expert network was a good phone directory, but nowhere close to the wealth of information stored in today’s browsable databases. GLG has experimented with many interesting business areas over the years. These include:

However, the 1h expert phone call has remained their core value proposition, according to former executives.

Major milestones for GLG:

“GLG cubs” – expert networks started by former employees


Further reading

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. In 2019, GLG generated close to $600m revenues and remains the largest expert network in the industry.

Finally, here’s GLG’s website.

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