When groups were introduced on LinkedIn, it really revolutionized the way a lot of us used the site. LinkedIn went from being a very one-dimensional platform to being a place where you could regularly engage with people who were interested in the same things that you are.

The first group I joined was one of the first groups created - my alumni group, Hamilton College. Dan Nye, the former CEO of LinkedIn was a Hamilton grad, so he created this group and invited all of the alums to join. They really took off from there. The latest number I found is that there are over 871,000 groups on LinkedIn, which is just incredible.

But don't worry, you don't have to browse through all of them.