The benefits of using AddEvent in event marketing include improved attendance rates, a seamless user experience, and the ability to automatically send RSVPs to HubSpot for conversions. By creating automated workflows, such as Zaps, attendees can be brought into the pipeline, allowing businesses to focus on conversions and drive revenue. With Zapier, users can automate almost any task at work by connecting AddEvent with other CRM tools, and building custom workflows to generate more ROI from events.