Desk is an all-in-one customer service tool allowing you to keep track of your customers across multiple channels including email, Twitter, Facebook, phone, and chat. Desk also makes it really easy to create knowledge bases about your products and services so customers can support themselves.
Using Desk with ActiveCampaign will allow you to sync your contacts between both applications.
Trigger automations when a case is created, updated, or resolved.
Add notes to a contact's record from exchanges between your support team and your contacts. Build automations to automate processes and not your relationships.