Checking the SERP of my site against many of my target keywords and looking at the #1 position for each of them.
In each case but one, it's a really ugly page with sub par information and then looking in Yahoo Site Explorer, it has tens of thousands or even hundreds of thousands of back links, the vast majority of which are clearly paid placements as their stuck on to hidden pages or jammed in a long list of links on a page by itself.
So Google always claims you shouldn't do this or you'll get penalized but it sure doesn't seem to be the case.
I have a hundred and some backlinks in yahoo site explorer, gained by doing what you're supposed to be doing (submitting articles, posting on good blogs and forums, getting on quality directories and gaining natural backlink spread due to good content) and yet I'm on the second or third page of SERP for all of these.
I have to fight the temptation every day to hire one of these services to go out and buy thousands of links for me, while I wait for Google to really change things to do what they say.
Any words of encouragement?