Dear Gib

Thanks so much for sharing your knowledge and insights with the rest of us. I feel like I have learned more from you than even people I've worked with professionally.

One thing I'm curious about here, for the first case, you tested for customer delight by measuring retention. I can see an argument for that- ultimately retention is what matters, but it seems a bit… blunt. Could you not get a clearer response from e.g. NPS? Or is the underlying hypothesis here that customers who aren't delighted will eventually churn?

The industry I work in is too small to properly utilise A/B testing, so it's always fascinating to me the inferences that can be drawn by virtue of having large sample sizes.

Cheers!

Jack