"extensive social network" is a correct and usable phrase in written English.
You can use it in sentences that describe a broad or large network of people connected through one another, either online or in-person. For example, "He has an extensive social network of friends and colleagues that he's been cultivating for years."
There's a really extensive social network around lowriding".
From the US, Gülen has run an extensive social network in Turkey, promoting interfaith dialogue and providing social services.
Overall, findings are consistent with the view that a high level of social capital (e.g., a favorable reputation, extensive social network, etc).
The leverage points were: reputation of research institute and/or scientists; raising and balancing expectations; communication about and investment in the scientific basis of the modelling work; participation in model development; heterogeneous and extensive social network in policy domain; institute mandate that secures availability of 'stepping stones'.
Emotionally/socially expressive individuals are friendly and usually have a fairly extensive social network.
Our investigation highlighted an extensive social network with multiple epidemiologic links (18 ).
A study of centenarians in Sardinia found that they tend to be physically active, have extensive social networks and maintain strong ties with family and friends.
They show high levels of engagement with 'emerging cultural capital' and have extensive social networks, so indicating that they are far from being disengaged in any conventional sense.
Political skill can enable individuals to effectively understand social cues (Ferris et al. 2005), and construct extensive social networks (Breland et al. 2007).
Compared with other existing models, our model has a very extensive and detailed social network, which may be important because individuals with more social interactions and extensive social networks may be more likely to spread influenza.
The ability to maintain spatially extensive social networks and a fluid social structure allows human foragers to "map onto" the landscape, mitigating the impact of ecological risk and conferring resilience.
