I've recently become more of a LinkedIn addict simply because the profiling is more detailed so I really know who I'm connecting with (to an extent). One thing I have noticed in the last one month is the amount of changes that take place on LinkedIn almost everyday.
I've just logged in this evening to find that the way my inbox is configured has changed and I like it. Only last night I was looking for a message from a new contact and found it difficult to identify because I couldn't remember her exact name but I knew she had recently sent me an invitation to connect.
Well, today as I logged in I saw that LinkedIn had separated the invitations from the messages. How useful is that! And I say that as opposed to Facebook's new 'Like' Ok...I thought that was what being a fan meant?' or Twitter's 'Retweets' that can't be edited'. As a business, it's important to keep innovating but I think considering how useful it will be to the end user should be priority.