How do Streams affect the display of overlay Campaigns and Offers? 

Streams take priority over overlay campaigns and offers. This applies to both outbound and inbound Streams:

• Outbound - when a visitor views pages inside a Stream, they won’t see any additional overlay campaigns and offers on the Stream pages.
• Inbound - when a visitor is presented with a Stream side menu as part of inbound personalization, he won’t see any additional overlay campaigns and offers on that page.

12. Explore the performance of your Streams by navigating to Activate → Analyze → Streams. Uncover the engagement and conversion metrics of the entire Stream, and see a breakdown of these metrics for each individual page. You can also explore the full journeys of visitors that passed via Streams by clicking on the numbers in Connected Contacts or Goals Completed.