To try and play devil's advocate: - They let users access a FAQ-like experience anywhere in your app. This is already easily done using tabs but it may help

To try and play devil's advocate: - They let users access a FAQ-like experience anywhere in your app. This is already easily done using tabs but it may help less technical users. - They often include a way of escalating to a real human. - I personally (and many others) find textual communication less stressful than a phone call. It probably lets the CS rep on the other end juggle more customers at once too.