Having to update many sites at once and even simultaneously makes it hard to keep track of all changes and can slow down your update process drastically. Each new site will increase the complexity and thus the workload. Outdated sites on the other hand will ultimately force you to relaunch them completely and render your sites more useless the more outdated they become. Content Sync allows you to create, update and delete content and media items all in one place and update all your sites at once. Changes are propagated quickly, allowing you to update your content continuously and with ease.
Using Content Pools you can also cherry pick content and media items individually per site.