Stop get_promotions_cached from combining campaigns on same link.
Rename get_promoted_links to sample_promoted_links.
Add caching to get_promotion_list and use namedtuple.
Cleanup in get_promotion_list.
CampaignBuilder don't combine campaigns on same link.
Split up the spotlight.
Delete randomized_promotion_list.
Loggedin spotlight: pick winner in advance.
Clean up lookups in spotlight.
Set data attributes on stubs.
Make a stub for each campaign.
Spotlight handles campaigns better.