Identifying content items for inclusion in a shared collection

A system comprising:

• a processor;
• a non-transitory computer-readable storage medium having stored therein instructions which, when executed by the processor, cause the processor to:
• receive from a first user having a first account at a synchronized online content management system, a request to share a collection with a second user having a second account at the synchronized online content management system;
• generate, in response to the request, a persistent pooled collection at the content management system based on the collection;
• transmit, to a device associated with the second user, an invitation to join the persistent pooled collection;
• upon the second user accepting the invitation, link the persistent pooled collection to the first account and the second account so that the first user and the second user have access to content items in the persistent pooled collection and have permission to contribute content items to the persistent pooled collection;
• scan second content items stored in the second account, based on a commonality, to identify additional content items to contribute to the persistent pooled collection;
• and
• add the additional content items to the persistent pooled collection.