How to upload eData Source seed lists to Salesforce Marketing Cloud and manage subscriber keys?

Key findings

• Subscriber key importance: SFMC relies on unique subscriber keys to manage contact data, distinct from email addresses. This allows for flexible data structures and prevents duplicate contact records for the same individual if they have multiple email addresses.
• Seed list integration: eDS seed lists can be directly uploaded to SFMC, typically into a dedicated data extension, to facilitate deliverability testing.
• Custom subscriber keys: Many organizations use non-email fields, such as member IDs or account IDs, as their subscriber keys in SFMC for better data management and segmentation. This often requires generating corresponding faux IDs for seed list entries.
• Testing with seed lists: Once uploaded, the seed list data extension can be included in sends, allowing marketers to monitor inbox placement across various ISPs and identify potential deliverability issues.

Key considerations

• Data consistency: Ensure the data structure of your eDS seed list (e.g., column names like 'MBR_ID' and 'EMAIL') matches the data extension fields in SFMC for seamless importing. This consistency also applies if you are testing email deliverability using seed lists with multiple content versions.
• Subscriber key strategy: If using custom subscriber keys (e.g., member IDs), a clear strategy is needed for generating unique, non-conflicting keys for seed list entries. This ensures the seeds are treated as distinct subscribers.
• Automation for testing: Consider automating the seed list upload and inclusion in sends via Journey Builder or Automation Studio for consistent and efficient deliverability monitoring. This helps when you test email deliverability across various campaigns.
• Data model impact: The choice of subscriber key (email vs. custom ID) significantly influences how data is structured and related within SFMC. This decision should align with your overall data architecture. More details on how Salesforce Marketing Cloud manages contact data can be found on Automation Champion.

Key opinions

• Faux IDs for seeds: Many marketers who use non-email subscriber keys (like member or account IDs) for their main subscriber base simply create artificial or 'faux' IDs for their seed list entries. They often use the seed email address itself as the faux ID to maintain a simple correlation.
• Direct upload to SFMC: Uploading the eData Source seed list directly into a specific data extension within SFMC is a common and effective method. This data extension can then be included in relevant sends.
• Consistency with data model: The general consensus is that maintaining a consistent data structure, even for seed lists, with fields like 'MBR_ID' and 'EMAIL', makes the process smoother and more reliable.
• Practical functionality: Marketers find that this approach for handling seed lists, regardless of the subscriber key setup, effectively serves their needs for deliverability testing and monitoring.

Key considerations

• Subscriber key choice: While 'email' can be a subscriber key, using a unique identifier like a member ID or account ID often provides greater flexibility for managing customer data across different systems, as highlighted by many users in the Salesforce Trailblazer Community.
• Seed list management: Marketers need a clear process for regularly updating and maintaining their seed lists to ensure they reflect current testing needs and accurately simulate real recipient behavior. This contributes to better inbox placement.
• Integration with existing processes: The process for uploading and utilizing seed lists should ideally integrate smoothly with existing email sending workflows to minimize manual effort and potential errors, ensuring you leverage essential deliverability tools.

Key opinions

• Foundational data strategy: Experts advocate for a robust foundational data strategy in SFMC, where the subscriber key is carefully chosen to represent a unique individual, rather than just an email address. This prevents issues with data duplication and subscriber tracking.
• Data extension design: The design of data extensions for seed lists should mirror the structure of your primary subscriber data extensions. This consistency ensures that messages are rendered and processed by SFMC in the same way for both test and live sends.
• Impact on deliverability metrics: Improper management of subscriber keys or seed list data can skew deliverability metrics, making it harder to accurately diagnose and resolve hard bounced email addresses and other deliverability issues.
• Testing validation: Experts recommend validating that seed list sends are indeed reflecting true inbox placement. This includes checking for any discrepancies in how SFMC processes seed list entries compared to regular subscribers.

Key considerations

• Unique identification: Ensure every seed list entry has a truly unique subscriber key. If you're using a system that generates non-email keys, create distinct, non-conflicting keys for your seed addresses. This prevents overwriting existing subscriber data or encountering errors during import.
• Data lifecycle management: Consider the lifecycle of your seed list data. Regularly clean or refresh your seed list to remove inactive or problematic addresses to ensure accurate and reliable testing results. This is similar to best practices for blocklist monitoring.
• Segmentation impact: The choice of subscriber key affects how you can segment and target messages within SFMC. A well-chosen key allows for more granular segmentation and personalization, which indirectly supports deliverability by improving engagement. For more on this, SpamResource highlights the importance of data segmentation.
• Testing environment consistency: Ensure your testing environment, including how seed lists are processed, closely mirrors your production environment. Any differences can lead to inaccurate deliverability insights.

Key findings

• Subscriber key definition: Salesforce Marketing Cloud defines the subscriber key as the primary key that uniquely identifies a subscriber across all applications in the Marketing Cloud Engagement account. It does not have to be an email address.
• Data extensions as primary storage: Documentation strongly recommends using data extensions for storing all subscriber data, including seed lists, due to their flexibility, scalability, and performance benefits compared to older list structures.
• Data relationships: Official guides explain how to establish relationships between data extensions using primary and foreign keys, allowing for complex data models that support advanced segmentation and personalization.
• Import methods: SFMC supports various import methods, including manual CSV uploads and automated file transfers, which can be used to bring eData Source seed lists into the platform.

Key considerations

• Consistency of subscriber key: Once a subscriber key is defined for a contact, it cannot be changed. This underscores the importance of a well-planned subscriber key strategy from the outset for both regular subscribers and seed list entries, as noted in Salesforce Marketing Associate certification materials.
• Primary key definition: When creating data extensions for seed lists, ensure the chosen subscriber key field is designated as the primary key and is set to be nullable based on your requirements, but for seed lists, it should always have a value.
• Data extension sendability: For a data extension to be used for sending, it must be marked as 'sendable,' with a designated subscriber key and email address field. This is crucial for your seed list data extension.
• Data retention policies: Implement appropriate data retention policies for your seed list data extensions to manage storage and ensure relevance of your testing data over time. The DESelect guide on managing data in Email Studio provides further context on data organization.