Cause Yahoo loves fresh content + links + EMD domains. Thats part of it anyway. Google hates lots of normal SEO practices but EMD still have some weight in Google just not as much as previous.
Your question makes little sense as phrased: only Google has PR, Yahoo does not include Google page rank. Perhaps you are asking why it's easier to rank for a keyword on Yahoo than on Google, then it's not for the reasons mentioned by GamingOn, which are BS (ignore them). I'll tell you the real reason. Yahoo does not do it's own search any more, it is powered internally by Bing. So Yahoo and Bing are essentially the same search engine, and the results are only a little different. Bing (and Yahoo) are easier to rank in because they are much like the old Google algorithm: they can be easily manipulated with cheap link building. Google has learned to identify link spam more easily, and it disregards bad links or even penalizes your site for them. Bing/Yahoo is less much less sophisticated that way. If you don't care about your Google rankingss (most people do!), you can still build sites that you can rank with cheap links, but only on Bing and Yahoo.
and Same answers and they are both right but philips just makes his answer more vague. Links are still a major factor on bing (and yahoo as it's the same) and google is not more complicated as they went reverse and rank high sites like amazon and ebay for complitely irrelevant keywords... and wikipedia is just nonsense for some keywords but still ranks high in google.
Search engines have different algorithms. I've also found it easier to rank well on Yahoo, especially after Panda, Penguin, and Hummingbird.
Yes, Yahoo is really less in the search game nowadays as they are into the social media business. They are gaining market share with Yahoo answers and developing an audience by having some interactive services like Yahoo Finance etc. Generally speaking, they are less competitive because fewer people focus on Yahoo and Google's algorithms are smarter and more sophisticated. SEO is a weird animal, you do all this work and then Google changes what it wants and your rankings plummet. This is true even if you do things the right way, i.e. solid content, authority links from quality blogs and social media sites, etc. I don't want to discourage SEO as it can be very powerful and lucrative but you have to be willing to accept that your sites might get slapped without any kind of warning or reason. Therefore, having lots of sites that rank well and do smaller volume is probably better than have a single site in a big market with a high power ranking that gets lots of traffic just because the game is changing and it's changing faster than anyone can keep up. Unless you are Amazon you're going to have to accept that this is how things go. Still, Google can only change the rules they can't eliminate the game altogether so if you want to do well in Internet Marketing or SEO you've got to have an active and luminous mind and stay on top of what's going on. Being a mad scientist is a boon in this business.
From my experience it is very easy to rank high on yahoo. All you need is keyword in domain or even title of the article and you will be on the first page for most keywords with low competition.
yahoo has different algorithms than google ,and they are easy to achieve... also yahoo indexed pages more faster than google.