let's make another one.... i see some links on my competitor site...hmm...i go to forums, make fake accounts and advertise that i sell links giving my competitor website...then i go report to google...it's not making sense...they cannot charge you for nothing...how to buy links? my friends friend has a friend who has a friend of a friend who sells links...tadaaa pretty easy..i don't believe this good guy bad guy google police
Yes, this is right. it is possible to do what you've just describe, but from other hand, will google check all WebMasters forum? even small one? I don't think so. Links sold through text links add are not so easy to detect - you need to do some nontrivial spy actions. Google prefer to do it automatically, because number of websites increased very fast and it is impossible to do manual checking.
everything in this world is measured thats why i think many people want good google page rank or alexa rankings
Because there are so many noobs and not-too-bright people. Hello? Look around you, they're every where. We all know that Google is number one, so why remind us? Why do they go with it, because it was Google's founding father's mathematical equation (algorithm) for predicting the likelihood of a site being visited. Nope, nothing (or very little) to do with SERP's. Ok, to be fair, perhaps all other things being equal (and when does that ever happen), maybe two identical sites, with identical SEO - content, keywords, etc. - maybe then, PR will help display one in front of the other. But, here again, this is the real world, and nothing's ever equal. I have observed many a site with high page rankings and low SERP's, and those with low page rankings and HIGH SERP's. It's obvious if you just look. Think about it.
Pagerank and SERPs are different things and high PR does not guarantee good SERPs. Trouble is people are wired up to like measuring things. That's why accountants exist.
http://www.webpronews.com/topnews/2009/10/15/google-ditches-pagerank-in-webmaster-tools which comes from http://www.google.com/support/forum/p/Webmasters/thread?tid=6a1d6250e26e9e48&hl=en Bye bye PR. It's been nice knowing you.