An event is a reason for people to meet

THE IDEA
"Marketing meetup" is vague. "How three local shops doubled their weekend traffic" is a reason to come. Clarity fills seats. Tell people exactly who the event is for and what they will be able to do afterward.
NAME THE TAKEAWAY
Finish this sentence: after this event, you will be able to do one specific thing. Put it in the title.
PICK THE ROOM SIZE
A small, full room beats a large, empty one. Match the promise to the audience you can actually reach.