A blocked advertiser is a brand a creator has added to their blocklist; blocking takes effect immediately for new offers and is silent to the advertiser, while any running flight is unaffected.
A brand a creator has added to their blocklist. Blocking takes effect immediately for new offers and is silent to the advertiser, who simply never gets a response, so a creator never has to fear social fallout for turning someone down. Any flight already running is unaffected.