All sessions (photos/GIFs/MP4s etc) will be live and viewable on a microsite (if one has been setup) for 2 years. After which the photos and associated data will be deleted.
Please note that if you do want the photos and data associated with the photos then please download the zip files and data from the event before it is deleted.
For long running events, each month the photos that are older than two years will be deleted but the photos under two years will still be accessible. The analytics, for example photo count, views and AVA, will still be accurate and include the deleted photos.
You will see a banner across your event dashboard to inform you each month which events will be affected (which events photos will be deleted from) so you can download them before they are deleted.