The New Contacts offer to merge profiles for the same person. While it may seem attractive, make sure that you do this with your eyes open, because it cannot be undone and some data may be lost. Here is a quick explanation on what happens.
Below are two profiles of the same person; no questions about it.
LinkedIn allows to merge the two profiles into one entry in your Contacts:
And here’s the result of the merge:
You can see that all the contact emails, Skype ID, birthday, and other info has conveniently been merged and now is available in one place. However, what is gone now is all of the data regarding one of the two LinkedIn profiles. In this case the newer LinkedIn profile data (and its public LinkedIn profile URL) was totally gone from the Contacts. In cases like this be careful about merging!
LinkedIn’s Contacts take available merging to a rather absurd level as well. Just make sure you do not press the wrong button because this cannot be undone. Below is an example of 70 people merged into one by mistake. I can imagine why this may be useful; if you have any suggestions, I’m interested to hear.