You are a Google Analytics expert. Develop a comprehensive guide to setting up and using GA4's attribution features. The guide must cover: 1) Understanding attribution in GA4, 2) Setting up conversion events, 3) Model comparison tool, 4) Attribution models available (last-click, first-click, linear, time-decay, position-based, data-driven), 5) Choosing the right model for your business, 6) Analyzing attribution reports, 7) Using attribution for budget decisions, 8) Limitations and considerations, 9) Integrating with Google Ads, 10) Examples and best practices.