How to build a win-back campaign that actually works
Short answer
Start the win-back sequence at 90 days of inactivity, lead with what they bought, and save the discount for the final email.
When to start
Ninety days is the sweet spot for most stores. Earlier and they are not truly lapsed. Later and they have forgotten you.
The three-email sequence
Email one: remind them what they bought and what is new. Email two: show what similar customers are buying. Email three: offer a small incentive with a deadline.
What not to do
Do not lead with a discount. It trains customers to wait for one. Do not send a single email — a sequence outperforms a one-shot every time.