I personally think there is a lot of smoke and mirrors in what Google says compared to how they actually operate. Google takes a lot of notice of the inbound link texts, but all this stuff about google understanding page theme/content is a load of rubbish. Yes, they do check to see if certain words about gambling and little blue pills etc are there, and they take into account sites with lots of random links to all sorts of stuff. BUT if someone linking to you has 3 or 4 links on a page only, and the anchor text matches what you are about, the rest of the page content doesn't really matter very much.
For instance - the main keyword of the company I work for in my "day job" is in an ultra competitive phrase online, the sort of phrase where everyone in the top 30 or so "gets" seo, and are all frantically trying to out-seo each other. We normally sit about the bottom of page 1 for the main key phrase - lets call it "blue widgets" (Reason we aren't higher is have only been doing SEO properly for the website for a short time as boss has finally seen reason only recently - was ranked 578th - page 57 - when I started working on it).
Now about 7 of the top 10 ranked sites in our industry have thousands of blatent paid links coming to them. As an example, the number 3 ranked company (who had a meteoric rise) has links from a huge number of sites that are not only completely unrelated to "blue widgets" but are not even in english (even when translated they are irrelevant)! They are mostly blogs and small businesses on any topic you can imagine and in a lot of cases the only two english words on the page are "blue widgets", in size 8 point somewhere inconspicuous, the rest of the page being in arabic, thai, russian, you name it.
Not only have google not realised this is an issue and devalued the links, but their rise has been on the back of it. And to the "google will find out eventually", well if their algorithm doesn't pick it up automatically and ignore the links (which it doesn't), the changes of them doing anything is next to nill EXCEPT for a few companies they manually find and them "make an example of" to discourgage others. I reported these paid links to google a couple months ago via the specific tool they have in the "webmaster tools" section to allow you to report page links and no action or response even then.
THAT SAID: 95% of the time you won't have to resort to this sort of thing, as most industries in Australia are not as competitive as this example. OR you can build just as many links by doing clever stuff like link bait when basic SEO principles don't give the results you want. I'm not advocating buying this type of links, it's
not the methods I use nor is it the only way, just pointing out that lots of people are doing it successfully without penalty. Most with experience in SEO will tell you that following the google guidelines to the letter and succeeding is tough when 99% of SEO's (even white hatters) are breaking them in some small way.
Matt
Marketing Web
http://www.marketingweb.com.au