I'm trying to built a community with professionals only, and as such it would be great if there would be an option to log in using the details of a linkedin account. As such their real name becomes the account name. In this case I want this the only way for people to join in.
This is not my experience. It is true that only a small percent of Linkedin users are active at conversions at Linkedin, but actually a very high percentage of Linkedin users at logged in at least weekly to check for announcements and maintain their network, and most Linkedin users can easily remember their username and passwords.