LinkedIn - LinkedIn is a business-oriented social networking service, mainly used for professional networking.

Eventbrite - Discover Great Events or Create Your Own & Sell Tickets

about.me - About.me lets you quickly build simple and visually elegant splash pages that points visitors to your content from around the web. Get started today.

Attendize Event Ticketing - Attendize is a free & open-source ticket selling and event management platform

pretix - pretix helps you to sell tickets for your event in an easy way. It supports multi-lingual events and provides a wide range of features

Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.