Well.. I think we never know what we can do with someone in the future. Like, you have a dream long time ago but have to postpone making come true for a reason. One day, you meet someone who have the similar dream as yours. Who knows it can become a collaborating opportunity, right? We sometimes don't need a reason to connect with someone else. Even if it cannot turn to a business relationship, we can still help each other in some ways, I guess.

You can share your dreams and interests with them - state what you are interested in and what is your base of knowledge - from that they may find similarities or even just an interest in helping. Maybe that is best place in your profile or maybe you phrase it as a question.

So, for example, say your dream has been to make a film. You could state that as a question "What would you suggest a person pursues in order to create a film?" See what your responses are like. It seems Anphabe has seen this in the question "How to speaker better English" that resulted in a great deal of discussion.

The next thing is : You should see any shared interests, stories, subject with the new ones. Try to contribute the really good things for them. Remember no one knows whom do we need in the future . So building the as many as possible friend in social network and in the reallife will increase your success proabilities

Unless you are a recruiter and want to have the biggest address book (without knowing what they are really doing), you should discuss and/or meet with them ; otherwise why connecting with them ?

Depend on you: What do you want with this relationship?