What's the breakeven point for offering recovery discounts?

As a Shopify store owner running ads in the competitive fashion space, I've been wrestling with a critical question: When does offering a recovery discount actually make financial sense? Every time a potential customer abandons their cart, I see potential revenue slipping away. But I can't just throw discounts at every visitor—that would destroy my margins. I've watched my ad spend climb steadily, and while traffic looks good, my conversion rate remains stubbornly flat. The real pain is knowing that some of these almost-customers just need a tiny nudge to complete their purchase. But how much of a nudge? A 5% discount? 10%? And at what point am I essentially paying people to take my products? I've tried generic discount codes, but they feel scattershot and imprecise. What I desperately need is a strategic approach that targets only the right visitors—those genuinely on the fence—without giving away unnecessary margin to customers who were already going to buy. My gut tells me there's a sweet spot where a well-timed, personalized offer can transform a potential loss into a profitable conversion. But finding that exact breakeven point feels like trying to hit a moving target in the dark.