Hello Friend, I want to add my site in yahoo also as i have submit in google adwords so please friend tell me that it will be beneficial for me like Google.
As far as ease of use, I like Google's interface a lot. It is a lot easier to set up and things are up and running within minutes. Changes you make on overture sometimes require a few days of editorial review. I'm going to be publishing an article in about a week on tips and tricks for optimal PPC. If you are interested, pm me and I'll send you the link once it's published.
yahoo ppc has less traffic. be sure to use phrase search instead of broad to get more targeted traffic
Don't bother with Yahoo PPC. But depends on what country you are in. Here in the UK I would say 'try it' as Yahoo still has some voice here. Give Bing a go instead, as they are taking market shares from both Google and Yahoo.