The majority of CEOs from leading US public (92%) and private (76%) companies, as well as the top CEOs in Silicon Valley (86%), are visible online in social media and on their company websites, according to Socialising Your CEO IV: The Engagement Factor, a new study in series of reports from Weber Shandwick.

“Due to the strong link between corporate reputation and CEO engagement, we are committed to better understanding how CEOs can adopt and leverage social media and other digital platforms to communicate, listen and respond,” says Andy Polansky, chief executive officer, Weber Shandwick.

The firm researched the online activities of CEOs from the top public companies in the U.S. Fortune 500 rankings, Fortune’s Most Important Private Companies in the U.S. and Mercury News’ top companies in Silicon Valley. The audit investigated three levels of CEO activity: public CEO visibility on the company website or on social networks; CEO posts from the past 12 months on the sites on which they are visible; and CEO engagement—any open dialogue between the CEO and site visitors—from the past 12 months.

“CEOs and other executives can amplify and deepen their company narratives by creating social content and sharing it online,” says Chris Perry, chief digital officer, Weber Shandwick. “More CEOs have made the leap to communicating online to help shape their brands digitally and personalize the company. However, we are now at a point where CEOs need to truly embrace social engagement and move it up the next notch.”

While public, private and Silicon Valley company CEOs excel in online presence, they are not making more extensive use of their platforms. Fewer than four in 10 public and private company CEOs (38% each) have posted online within the past year. Silicon Valley CEOs have a slightly higher posting rate (41%), but not by much.

Engagement levels are also low, with 22% of public company CEOs and 34% of private company CEOs interacting with other people online within the past year. Silicon Valley CEOs are the most engaging of the chief executives included in the audit (39%), just surpassing private company CEOs. It is noteworthy that when private and Silicon Valley company CEOs post, they typically engage.

“Engagement is the new presence when it comes to CEO sociability,” says Leslie Gaines-Ross, chief reputation strategist, Weber Shandwick. “Distributing content online and engaging with stakeholders allows CEOs to humanise the conversation, demonstrate transparency and touchability, forge connections with stakeholders and to achieve the reputational advantage. Social engagement is more important than ever in this highly politicised climate and preparation is key.”

The company website is the top destination for public and private company CEO visibility with 90% of public company CEOs and 66% of private company CEOs having a presence beyond just their name and standard biography page

But social networks are the top platform for Silicon Valley CEO visibility (71%), far surpassing the social network presence of public (50%) and private company CEOs (59%). Silicon Valley CEOs also lead in video use, with 65% appearing in company video, either on the company website or company YouTube channel.