Help versus control
Rejoiner and Drip are both reasonable ecommerce retention choices. The difference is whether you want help or control.
Rejoiner leans toward help. Drip leans toward control. That is the decision.
Where Rejoiner wins
Rejoiner wins when a store needs strategy and execution support around lifecycle email, SMS, and cart recovery.
Where Drip wins
Drip wins when the marketing team wants to own the workflow builder and iterate directly.
Where Sequenzy fits
Sequenzy fits when the team wants email automation without managed services or deeper ecommerce complexity.