I have a customer who is wanting to use Campaign Monitor and is wondering if campaign activity (i.e. opens, clicks, unsubs, etc) will feed into HubSpot from emails that are sent via campaign monitor? I don't think this is possible, since the emails are sent outside of HubSpot, but then again I see that you can sync certain fields such as marketing email open, click, etc.... Any insight?
You're right in your assumption that campaign activity will not be synced between the two apps. That data isn't part of the objects we can sync at the moment.
If there are data fields like "marketing email open, click" available, then those data fields will likely the average number of clicks and opens for that record.