What makes people click?

Experian's company "hitwise" tracks the market share that Internet news agencies have http://tinyurl.com/2qcd2n. The most popular by far is Yahoo news and it makes me wonder what makes them almost twice as popular than its closest competitor CNN.com. First, I thought it may simply be the case that many have Yahoo as their homepage and get a lot of hits for not really trying. Well that may be the case, but Google is also a popular homepage, but its news service is used less than half as much as Yahoo News. I compared the top 10 sites and Yahoo is appealing to the eye, and easy to navigate, but so are the others. I will make an exception that Google News is visually abrasive and thus harder to navigate. Maybe its popularity comes from a public sense that Yahoo is a news consolidating website and not a news gathering or writing site? There is some truth to that, but then why would Google rank so low and CNN rank so high? Advertisers? eh hard case to make. Stories? nothing really unique here. What is it? I know my mouse clicks when I have news that is reliable, unique, appealing to the eye, and compelling. I know I am not breaking new ground with my opinions here but why is Yahoo so huge? Aren't they being bought out by Microsoft? Weren't they almost a failure 5 years ago? What is going on? I'm not angry, I just want to know so I can make a good career choice by knowing what makes people click.