Why Multi Org ? Having all sales , service and marketing clouds on a single org is no more a good practice from overall Org strategy point of view. Having everything on one instance makes sense from data availability point of view but this is not more an excuse since near real time data can be access using various channels on Salesforce platform. Having everything in one org have some other limitations , to start with the governor limits which can be seen in terms of code character usage , data storage constraints , sharing related issues like hiding sales data to anyone else in the org who are not intended to know those. While moving Sales , Service & Marketing clouds into separate Orgs solves all these problems. Hub Org should be the Master Org where all the Orgs data is synced. This Org can be used for analytics purpose and also can act as backup database. There may be instances where Service cloud need to see sales cloud data. For example , Case ...