Inviting someone to use TeamData is as easy as entering their email in a Bundle to add them as a collaborator. The invitee will get an email to sign up and will see the information you shared.
Try to email employees at their work email. They will have to register with that email to see the data you shared. They can add other emails later if they want to ensure that shared data outside the office reaches their account as well.
Remember that others will see the data exactly as you create it, so it helps to invest the time up front to create enough information to show them the full benefits.
You might send a separate note explaining why you chose to use TeamData and explaining the benefits.
(The premium version has specific directions on inviting users.)