LinkedIn

I've found another problem with LinkedIn, one that I just realized, mainly that a lot of people try to add you to their network despite the fact you barely know them or have only worked for them for a short period of time. Now, I might be wrong about this, but I thought one of the main points of LinkedIn is to help you find a job and that works by having people you know who would recommend you recommend you. The thing is if you don't really know the person, why would they recommend you or help you in such a way? If, say, I only worked with somebody for like a month and barely at that, why would I even think of contacting them or having them say something to help you? Or am I just assuming that everybody on my contact list will automatically help me because I know them slightly? Or is this just me reading way too much into all of this and should go with it?

I guess what I'm saying is that so far, LinkedIn has been useless.