When you use the "register interest" button on a detail page, the exhibitor receives a connection request from you in their backoffice. At that point, they may choose to contact you directly via chat or video chat. Alternatively, one of the exhibitor’s staff members may choose to accept your connection request, and thus become your connection. They will then have access to your contact information, such as email and phone number, which they wouldn’t be able to see unless you were connected - with the same being true the other way around as well.