If you work in Social Business, you know that culture is a crucial aspect when introducing social networks. This is also reflected in the statistics. While my friends on Facebook show no correlation between region, culture and likelihood of post, my contacts on “professional” networks do. German customers and business partners have been very active, but none of the US were (except when connecting on Facebook). There are multiple reasons, including the fact that age is a non-topic at work in the US (equal opportunity) and that LinkedIn does not provide a reminder for birthdays of your contacts (unlike the German rival, XING).