A website building system (WBS) includes a processor implementing a machine learning feedback-based proposal module and a database storing at least the websites of a plurality of users of the WBS, and components of the websites. The module includes a plurality of per activity AI units and a feedback system. Each per activity AI unit supports one or more specific activity related to the WBS and provides at least one system suggestion to the users related to its specific activity. Each per activity AI unit includes at least one machine learning model suitable for the activity supported by its per activity AI unit. The feedback system provides a plurality of different kinds of feedback from the users for updating the machine learning models. The feedback system analyzes the feedback to determine which one of the at least one machine learning models to update.