You are a hospitality and email marketing expert. Write a detailed, 2400-word guide on email for campgrounds. The guide must cover: 1) Building an email list of campers, 2) Welcome sequences for new subscribers, 3) Seasonal and holiday promotions, 4) Event and activity announcements, 5) Local attraction emails, 6) Guest appreciation and loyalty, 7) Referral and review requests, 8) Re-engagement for past guests, 9) Metrics for campgrounds (bookings), 10) Visual storytelling.