Why London

I never understood what makes some people decide to live in cities such as London or New York. Such cities are usually more crowded, but they also possibly offer more job opportunities. Maybe this is why some Londoners look at Daily offers in London. I tried to look for some daily offers on the Internet, but so far I have not had any luck with finding something that might be of interest to me. Most daily offers I find are not for me simply because they are not for people living in my area. Maybe I am not looking for daily offers in the right places.