The ease of use. It's easy to set up and get started right away. I love that it integrates well with other tools like Salesforce and Hubspot. There are many features and options that you can configure. You can make it look exactly how you want it to. If you need help, they will walk you through everything step by step. They have a great support team. We've been using Black Pearl for over 2 years now and haven't had any problems. We're able to track our open rates, click rates, and reply rate in real time. It has made us more efficient as an organization and helped us improve our overall engagement.