Can I pay for my colleagues?

Yes. You need to do three steps: 1) purchase the right number of licenses, 2) create an organization then 3) invite colleagues.

#1 Purchase licenses

Go to Billing, subscribe to a plan, and choose the right quantity of licenses. You need to purchase a license for each person you will be paying for. 

#2 Create an organization

Go to Organizations, click "Create a new organization", and type in a name. Make sure that "Centralized Billing" is enabled, allowing you to pay for your colleagues.

#2 Invite colleagues

Open the organization you recently created and click on "Invite Colleagues". You will be able to invite a member for each unused license you have.