What type of platform should a brand or agency hire to run its Audience Deals campaign?

A DSP (Demand Side Platform) is the correct choice because it's the technology that allows advertisers (brands or agencies) to buy ad impressions programmatically. Audience Deals are a form of programmatic buying where specific audience segments are targeted. A DSP enables the advertiser to bid on these impressions, manage campaigns, and optimize targeting based on audience data. A DMP (Data Management Platform) collects and organizes audience data but doesn't execute media buys. An SSP/Exchange (Supply Side Platform) is used by publishers to sell their ad inventory, not by advertisers to buy it.