i am not agree with avoiding buying links.i bought links(after penguin updates in 2013) for my website and for my customers and i get good result!(i buy links many natural) but i am surprised that many people say dont buy links.even they say dont BUILD links! i ask a question about link building in google forum and all of people say me stop link building! in many of article about seo, is writen that buy links is very dangerous after recent google update! in my opinion,if links not effective and not important,google never said that dont buy or sell links!(specific follow links) also, in many websites, you can not rely on content and wait to others links to you!(natural).because some subject is not content base. also, in many subjects, you can not focus on related website to link you.for example,selling credit simcard charge is a public subject!and any website with any content,can link you as a usefull website(even sitewide links!)! at least, many people say google is very smart.if you buy links,sooner or later,google will detect you and penalize your site! Do you think this is true?