Create sign-up units

• Test sign-up units with A/B tests
• What are sign-up units?
• Create a new sign-up unit
• Use templates to build sign-up units
• Create email-only sign-up units
• Add Spin to Win to a sign-up unit
• Add a pre-engagement page to a sign-up unit
• Add a social proof metric to a sign-up unit
• Create a giveaway
• Design a sign-up unit
• Add an offer and a welcome journey
• Set display rules
• Review a sign-up unit