What is the difference between Total and Main revenue?

Legacy Hootsuite Ads reports conversion revenue for the Main Goal of a campaign, and if you are tracking multiple conversion events with a Facebook pixel, also reports revenue from all your conversion events combined. Set the value of each of your standard conversion events within the Facebook pixel.

• Main revenue - This metric reports only conversions for your main goal.
  On the Ads Design step (2) of campaign creation, you decide which event is the Main goal for the campaign under Goal Tracking. More details.
• Total revenue - This metric reports conversions for all the events that occurred as a result of the campaign.

These metrics are found in the campaign’s Dashboard, in the main graph, and in the Goals/Conversions widget. Displaying revenue must be enabled in your dashboard settings.

Example:
When creating a campaign we choose Purchase as the main goal, and have attached a value of $100 to the purchase event. We decide to also track another event, that sends revenue information when it occurs, like Newsletter Subscription (for example, you know that subscribers have an added lifetime value of $15, and you are also tracking those subscriptions to your newsletter).

In the campaign’s dashboard, the Main revenue metric will display conversions for Purchase, so it will show $100 every time a purchase event occurs. The Total revenue metric will display conversions for all events we’re tracking, so both the Purchase and Newsletter Subscription events. If a user made a subscription and purchased from your site, it will show $115.