aristotle - 1:47 pm on Aug 4, 2013 (gmt 0)
Have you been living under a rock? This is exactly what some people have been moaning about recently. You don't even have to buy a penalised site, you can buy 'SEO' packages that will wreck a competitors rankings extremely cheaply.
Apparently you're confusing two different things. Those "SEO packages" work (or try to work) a different way.