I send out nurturing emails for a service membership. The emails deploy to active members.

The emails are not promotional nor are they transactional. Or Are They? I need your opinion!!

The emails encouraging the member to get involved and USE a feature they've not used in the tool before. It doesn't promote new product or services.
It just encourages them to utilize an existing feature that they haven't done so yet.

My Questions - Must I insert an Unsubscribe link to be compliant with Can Spam?

Is this type of email considered Promotional or Transactional?