There are multiple ways to add someone to a Campaign.
If you're starting communication with a prospect or customer, you can use Add to Campaign from any page in our web application, or from Salesforce.
This flow will allow you to preview, edit, and schedule your first email in the Campaign, and if your Campaign starts with a task, these tasks will get queued for you in your Tasks list in our web application and in Salesforce.
You can do this from the Campaigns tab in our web application.
You can find the Add to Campaign button on the Conversations and People pages in our web application.
If you are following up with a prospect or customer from your Gmail or Outlook inbox, you can add them to a Campaign via your compose window when you follow up with them (if the first step in the Campaign is an Email).
Just reply to their email and choose a Campaign from our plugin.