What is the recommended action for importing contacts gathered from an external web form at high frequency?

The optimal choice in this context is to recreate the external web form inside Marketing Cloud. By doing this, you ensure that the data collected is seamlessly integrated into the Marketing Cloud platform, allowing for real-time processing and immediate use in campaigns or communication strategies. This integration reduces the likelihood of data discrepancies and ensures compliance with data management and privacy standards. Additionally, managing the form directly within Marketing Cloud provides an easier way to access and manipulate the data, improving operational efficiency.

While other methods involve transferring or syncing data from an external system, they can introduce delays and potential complications. For example, pushing each new record via an API may create excessive load and could lead to throttling issues if done at high frequency. Bulk exporting to SFTP would not be efficient for high-frequency updates, as it results in delays in data availability. Utilizing Journey Builder for Journey Data Sources could work but may not be the most straightforward option compared to embedding the form within Marketing Cloud directly. Therefore, rebuilding the form in Marketing Cloud represents the most effective approach for managing high-frequency data imports.