Don't all subscription services get 15% after the first year? Is Amazon getting that from the very first year, is that what's different here?
Depending on the product, you could be losing a significant portion of your customer base before then. For example Netflix, known for insanely good retention, loses nearly 40% of customers by month 12. [1]
[1] https://secondmeasure.com/datapoints/netflix-disney-plus-app...