What do you think si a better way to generate traffic to a web site through Linkedin: Joining relevant User Groups or Inviting Users to Your Group?
Linkedin is a social network, you can generate traffic by both ways. but as per my knowledge, if you don't do regular activities in any social network site, then you'll be banned from the network. be active participant in Linkedin.
All social networks frown upon self promotion and you therefore would have to bit cautious while doing. Linkedin a good way to have a online presence apart from you main website. Joining groups as well as having your own group is a good start. What I find more useful if the Q&A section. You can actively participate in answering questions and would help you to get some visitors who would come to your website looking for more. You could also post questions and start a discussion to instigate curiosity.