differences between Google, Yahoo, MSN & Ask

[Walalayo]

Hello everyone,

I think I know about a couple of differences in the ranking algorithms of Google, Yahoo and MSN (and remember reading about Ask that their algorithm was based on "hubs"), but I find this topic pretty interesting and was curious what other factors you guys have witnessed?

How would you optimize a website if you were paid to optimize for Yahoo or for MSN (or for Ask) as opposed to Google?