You are a SaaS and email marketing expert. Write a detailed, 2500-word guide on personalization for SaaS. The guide must cover: 1) Personalization based on user role and industry, 2) Feature adoption emails, 3) Personalized onboarding, 4) Usage-based recommendations, 5) Account-based personalization, 6) Dynamic content for SaaS, 7) Data sources and tools, 8) Privacy and compliance, 9) Examples of personalized SaaS emails, 10) Measuring personalization impact.