Grow will track "Events" in your Google Analytics. Go to Behavior > Events > Overview > Event Category and Grow will show up as an event once people start using it.
To get to the individual event actions, click on grow.me under Event Category
Then click on Event Action
Below is a list of the various events that Grow displays via Google Analytics and what they represent.
Google Analytics Events
Favorites
favorite - This counts how many times someone clicks the heart button on the main widget.
favorite_from_create - When someone uses the save button in a Create card.
favorite_from_sdk - When someone uses the save button in WPRM.
Recommended Content
recs_in_content_click - This counts how many times a reader clicks one of the links via the inline recommended content widget.
recs_scroll_carousel_click - This counts how many times a reader clicks one of the links via the header carousel.
recs_sidebar_click - This is when someone clicks on the sidebar recommended content widget.
Bookmarks
view_bookmarks - When someone clicks on the bookmarks link in the widget.
bookmark_result_click - When someone clicks back to your site from their bookmark screen.
Widget
tooltip_learn_more_click - This is when someone clicks the learn more link in the Tooltip that appears when users are signed out.
tooltip_sign_up_click - When someone clicks to sign up for Grow through the tooltip that appears when users are signed out.
open_widget_menu_click - This is counting the number of times the Grow menu is opening.
login_success - When someone logs in via the widget.
sign_up_success - When someone signs up via the main Grow widget
Share
share_pinterest - This is when someone uses the Pinterest share button within the widget.
share_facebook - This is when someone uses the Facebook share button within the widget.
share_twitter - This is when someone uses the Twitter share button within the widget.
share_from_search_click - This is when someone clicks the share button while in the search screen.
Search
search_result_click - This is when someone clicks a search result.
open_search - This is when someone opens the search view.
Subscribe
subscribe_sign_up_click - This is when someone clicks to sign up through Spotlight Subscribe.
subscribe_inline_success - This is when someone successfully signs up through Spotlight Subscribe.
This list is likely to update as new features are added!