I see ranking high in Google is much easier then Yahoo and Bing. When I build backlinks regularly I see my rank in Google SERP increase everyday and I can rank on first page for low and semi competitive keywords usually within 1 month.
But Yahoo and Bing do not provide fast result like Google. These two SEs take time and they even don't respond to quality backlinks like Google.
So ranking high in Yahoo and Bing is tough then Google? Why?