The technology that goes into web cameras has become so refined that it is small enough to fit into a laptop, and it is odd to see a laptop without an integrated cam. However, in a laptop, just as in a phone, a front facing camera is likely to have a low megapixel count, and the quality with which it can take pictures and record/stream video is very limited.
To have a decent experience using online video chat programs, you will need to buy a separate webcam, one which is not limited by having to be conveniently small, and specialises in what it does. Often times, just being connected by voice is not enough, and video connections have become essential. From Skype to Google Hangouts, web cams are useful for so many programs.