The Adobe Campaign APIs are not designed or intended to be used for bulk inserts into the recipient or any other large volume table in the platform's database. Instead, the developer or marketing user should be loading flat files which have been FTP’d to Adobe Campaign server to load any data in bulk.
Other options include querying local datamart tables (using mapped tables or FDA) when Adobe Campaign is installed on-premise or use the CRM connector to pull data into the system from other sources in bulk in a technical workflow.
API calls should be used for queries, updates, or one-time inserts into the Adobe Campaign database. The API should never be used for bulk inserts.
If these best practices are not followed, the Adobe Campaign application could experience performance or stability issues and/or loss of service due to improper design of data flows into the system.