Expanding your network on LinkedIn is easy; you just hit the blue “Connect” button and wait to see if the people are going to accept or not.
If they accept it, you will add new people into your network, and that’s it.
Yes, this is the easiest way to build a network on LinkedIn. You don’t need any special reason to add them, or even need to know them. If you want to connect someone, that blue “Connect” button is there for you.
More information: http://recruitingdaily.com/bigger-not-always-better-especially-linkedin-conections/