Reply is a marketing automation platform that focuses on lead generation and sales engagement. It allows businesses to automate their sales process through personalized email campaigns, social media, and website tracking. On the other hand, Infusionsoft is a CRM platform that combines contact management, marketing automation, and eCommerce capabilities. It helps businesses manage customer interactions, automate their marketing campaigns, and manage their sales pipeline. The key difference between the two platforms is that Reply is more focused on marketing and sales engagement, while Infusionsoft is more focused on overall customer relationship management. While both platforms offer automation capabilities, Infusionsoft offers a more comprehensive set of features for managing every aspect of the customer journey.