The perfect ad in your research folder now opens a broken video link. The caption survives, the advertiser changed its name and nobody remembers which country was selected.
A creative archive needs more than a bookmark if you plan to use it as evidence later.
Preserve the observation
Store the source identifier, source URL, advertiser, app match, first and last observation times, market filters and visible creative metadata. Keep the retrieval timestamp distinct from any campaign date the source provides.
Where access and reuse rights permit, retain a bounded copy of the media with its provenance. Do not assume that a publicly accessible file is automatically available for unrestricted republication or commercial redistribution.
Expect links to disappear
A remote media URL may expire or stop working. Show a clear unavailable state instead of an endless loading spinner. Preserve the original source link and metadata so the user can understand what was observed.
If you maintain copies, set limits for file size, media type, retention and storage cost. Validate fetched destinations and redirects so an importer cannot be used to request private network resources.
Make freshness visible
An old creative can be a useful design reference while being poor evidence of a current campaign. Label those uses separately. “Observed last month” is a stronger description than an unexplained green “active” badge that never expires.
For a personal swipe file, a simple review date may be enough. For a product serving customers, failed fetches, stale sources and incorrect matches require an operating workflow.
The best archive makes it easy to distinguish what the source said, what you saved and what you can still verify. That is less glamorous than a wall of autoplaying videos, but considerably more useful when someone makes a business decision from it.