If you’re going to openly sell crap links on the footer of your site to Mesothelioma Lawyers, Ticket Scalpers, Personal Injury Law Firms and other blatant spam related and irrelevant sites (sites which are not relevant to your own), Google is going to find you out and probably penalize you.
Such is the case of NewsDay.com, which was slapped with a Google Penalty for openly selling spam links throughout their high profile site.
Barry Schwartz points to a Google Groups thread where a Googler responds to the NewsDay.com PageRank issue :
Thanks for your post. I’m glad you’re posting here in the Webmaster Help Group, because the discussions here help educate webmasters around the globe. I just checked over newsday.com and compared it to the most recent version of newsday.com that was indexed by Archive.org: http://web.archive.org/web/20070829225145/http://www.newsday.com/
Scrolling near the bottom of what your site used to look like, I see the following “Featured Links”: Mesothelioma Lawyer Lung Cancer Personal Injury Law Firm Buy Mets Tickets Buy Yankees Tickets Wicked Tickets Hamptons Travel
Please remember that participating in link schemes intended to manipulate search engine rankings, including buying or selling links that pass PageRank, is a violation of our Webmaster Guidelines, and may impact your site’s standing in Google: http://www.google.com/support/webmasters/bin/answer.py?answer=66356
If you believe your site was at one point in violation of the Webmaster Guidelines, and you have since made changes to your site so that it fits within the guidelines, you can request reconsideration of your site by following the steps here: http://www.google.com/support/webmasters/bin/answer.py?answer=35843
Don’t play with fire, or you’ll get burnt. Thus is what happened to NewsDay.com, which was knocked from a PageRank 8 to a PageRank 5 (and seems to be back up to an 8 now). If you are going to sell links, or buy links, or do whatever with links, make sure that the links are contextually relevant and not obvious ad buys.
And if you own a legit website and get an email from someone asking to link to their personal injury sites and casino sites for $500 a month, tell them no (unless your site is about gambling or personal injury lawyers, then perhaps something can be worked out).