A recent poll shows that if you want to reach a CFO, you probably shouldn't go looking for them on Facebook or Twitter, as only 18 percent prefer to use social media to keep up with colleagues versus email, according to the Wall Street Journal. This is a dramatic drop since the last time the poll was taken in 2012, when 45 percent of CEOs said they prefer social media. So what is the best way to contact a CFO in 2015? Apparently email: 50 percent use it as their primary professional networking method, according to the survey. 

This could be indicative of a more cautious attitude to social media, with CFOs seeking to avoid making a statements in public that could come back to haunt them later or, even worse, saying something embarrassing that becomes a PR liability.

It could also be that CFOs are concerned about how much time it takes to be truly engaged: in another survey, 51 percent said their biggest concern about employees using social media at work was that it wastes time.