What are some alternatives?
Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community
ZenDesk - Zendesk is a beautiful, lightweight help-desk solution.
Salesforce Service Cloud - Service Cloud integrates customer service with social networks and provides a self-service customer portal and knowledge base system.
HelpScout - Help Scout is a simple, straightforward way to provide excellent support
Zoho Desk - Industry's first context-aware Helpdesk Software
Kayako - Help Desk Software and Customer Service Software by Kayako. Improve customer satisfaction, increase sales.