From the About page:
3121 is also a tool for collaboration: through our recommendation engine and with flexible, easy to navigate group pages, 3121 acts as a tool to help people better connect with relevant staffers to get their job done.(h/t Bloggasm)
3121 puts you in control and allows for a customizable dashboard and customized news. The more you get to know the system and the more we get to know you, the more 3121 will rearrange and deliver you what you need, when and where you need it. From news on your issue and Member, to positioning your own profile and collaboration tools front and center, we give you what you need to make it your own.