Well attended
Definition 1 of 1
Pro Tip 1/3Popularity Indication
Use 'well attended' to suggest an event's popularity or success in attracting people. 
The book signing was well attended, indicating the author's popularity.
Pro Tip 2/3Positive Outcome
'Well attended' often carries a positive connotation, implying that the event was not only populated but also enjoyed by the attendees. 
The fundraiser was well attended, and everyone seemed to have a great time.
Pro Tip 3/3Event Promotion
When promoting future events, mentioning past ones were 'well attended' can encourage more interest. 
Join us for our annual gala, always a well attended and splendid occasion!