OpenAI Bolted Custom Audiences Onto ChatGPT Ads Mid-Upfront Week
OpenAI added a custom audience upload to ChatGPT Ads on May 14, 2026, accepting CSV or TXT files up to 512MB of raw or SHA-256 hashed emails and phone numbers. A 512MB file holds roughly 7.8 million identifiers. The feature landed three days into the $30.99 billion TV