If I were to design a notification system for book lovers, I’d keep it razor‑sharp and data‑driven. First, pull in user data—reading habits, genre preferences, purchase history, even time of day they usually log on. Next, segment the audience into a few key groups: binge readers, occasional browsers, genre specialists, and the wanderers who need a nudge. Then, craft three tiers of alerts: a quick “new release in your favorite series” ping, a richer “handpicked titles you might like” email with brief synopses, and a weekly digest that blends the two for the more casual fans. Each alert includes a clear call‑to‑action and an easy way to silence or adjust the frequency, so users don’t feel spammed. Finally, run A/B tests on subject lines, timing, and format, then feed the results back into the algorithm to keep improving relevance. That way the system stays efficient, personalized, and respects the reader’s inbox.