Everytime we see a new feature popping up on Facebook, some xyz company is getting hurt. It is very uncommon these days to see some really unique feature from the main players. They are upto copying a lot of features from other proven products, I am pretty sure you are with me on that. The main advantage with facebook is its HUGE userbase. It makes it very easy for facebook to kill any existing product within no time (provided the implementations are really awesome).
Facebook lets you list your relatives in your profile, linking of family members was first started by Geni. Not many would have heard of Geni, but I am pretty sure many more users would have listed their relatives on facebook.
Next up, facebook places. Location based social networking is not something new, there are a number of players in this front: foursquare, gowalla, loopt etc. Here are some statistics on a small data set. Its quite clear that facebook is giving a stiff competition to foursquare in-spite of coming late into the market.
Another startup which was all over the news » Groupon which offered great deals on group buying. Google tried hard to buy groupon, but they couldn't so they ended up building google offers. Similarly facebook started deals.
Anyone using Facebook mail?! at least I don't know anyone using it. With all the hype given to the facebook mail. I expected it to be great, unfortunately I have never sent out single email from my facebook email id. I just don't feel like using it. GMail is rock solid! Additionally, I feel that employees at facebook lost some exclusivity by giving out the @facebook.com mail id to every tom dick and harry .
Facebook lets you add your workplace, projects worked on, people you have worked with, the time period and finally the description. This is a whole lot of information and that's pretty much what LinkedIn has been doing from the past few years. In a few days, facebook will suggest you jobs, just like how it suggests friends now
I wonder how startups will survive when someone as big as facebook enters their territory!