When it comes to retargeting for lead gen, which is considered a best practice for audience size and scale?

For retargeting lead generation campaigns, a best practice for audience size and scale is to target audiences of at least 1,000 individuals who have opened but not yet submitted a form within the last 90 days. This threshold (1K+) ensures a sufficient audience size for effective ad delivery and optimization, while the 90-day window captures recent interest without being overly broad. Targeting those who have opened but not submitted indicates a strong intent to engage, making them prime candidates for retargeting. Options like "50K+ for open not submitted in the past 60 days" are unnecessarily large and might dilute targeting efficiency, while "50K+ for video in the past 30 days" focuses on a different engagement type and a shorter timeframe, which may not be as effective for lead gen form submissions.