All will depend on the number of contacts you are sharing as well as the number of users you are sharing them with. The first share generally takes less than 5 minutes. However, the updated contacts synchronize instantly if the user utilizes one of our applications (web app, mobile app, Gmail add-on). The automatic update also occurs when they have installed our plug-ins on their Google Contacts manager. For contacts updated with other means, the synchronization frequency is around every 20 minutes.