What are some alternatives?
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Emamo - Simple event tools for organizations. One central hub to manage your events and members — all year long.
Eventbrite - Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
uGetTogether - A better way to help uGetTogether
Meetabit - All the local tech and startup meetups in one place - easy to organize & attend
Picatic - Picatic encourages event organizers to create a custom website, sell tickets and then determined their cost of use. Selling out events is easy with Picatic.