You can invite co-founders, team members, friends, family and even rivals by simply navigating to Search groups + connections from the side panel.
You can simply invite using an email address individually and invite them to join a group. You can add as many group members as you want, the sky's the limit. If you want to add in more than 5 members, you can simply upgrade your account by clicking on your profile avatar, then go to billing and choose the plan best for you.
As soon as your invitee becomes a ‘contact’ in F4S, they will appear in your Compare with connections section in the right panel. You will now have access to compare your motivations with each other by ticking the box next to their names.