I'd like to integrate my ERP system with constant contact, but I'm finding that this seems to be much more difficult than I thought.
For example, I found this text in the docs:
The use of this API to create a contact is designed to handle a small number of contacts (i.e. less than 25). To add a large number of contacts, use the Activities API resource. (As discussed in the Constant Contact API Terms and Conditions, intentional and unintentional misuse of this discrete API to frequently manage large sets of contacts is subject to API access or account termination).
I'd like to write a routine that takes all of the new addresses in the system every night and adds them into Constant Contact. This legalese seems to indicate that I need to write two integration routines, and one for days with 25 or fewer new contacts and another for days with more. This seems like a crazy rule, and doubles the work needed to become a Constant Contact customer.
I do understand the problem you are running into, and I would like to help you with your problem.
The activities API was created for exactly what you are trying to do, doing bulk imports periodically to the system. If sometimes your importing is less than 25, that is fine, as long as you are using the bulk importing API to do bulk imports, and not using it as part of a sign up box where only one contact is being uploaded at a time.
If you have any questions please let us know.