The funny thing is that I do used Xing, the European competitor to LinkedIn, and even though I have more contacts in LinkedIn, I really don't use it.
In Germany when I go to business events almost everybody hits up the people whose business cards they were handed within a day or so; in the US I've tried the same to discover that a large percentage of the people that I meet at founders' meetups aren't on LinkedIn.
The first use case makes a lot of sense for me -- if nothing else, it's an easy way to convert a business card to a vCard and have contact info track the person in question over time.
In Germany when I go to business events almost everybody hits up the people whose business cards they were handed within a day or so; in the US I've tried the same to discover that a large percentage of the people that I meet at founders' meetups aren't on LinkedIn.
The first use case makes a lot of sense for me -- if nothing else, it's an easy way to convert a business card to a vCard and have contact info track the person in question over time.