Buying Links for SEO
There is a debate raging over paid links as part of an SEO plan. Should it be done? Does it fall within White Hat SEO techniques? What do the search engines say about this? Is there a risk involved with buying incoming links? There are so many questions brought up with this issue, but let's cover a few of the big ones:
First off, search engines don't like the fact that webmasters can indirectly buy rankings, since obtaining good quality, relevant links theoretically helps your rankings rise. It also lowers the quality of links on the web when webmasters start linking for SEO instead of for visitors and quality. Matt Cutts has a good blog on this topic here: http://www.mattcutts.com/blog/text-links-and-pagerank/
So right off the bat we know that link buying is a Black Hat SEO method because Google has said it does not condone it. Paid directory listings are different because human eyes validate these links upon submission as being relevant and useful to their core audience. Business directory listings will always have a place in the heart of search engines, but buying thousands of site-wide links strictly for SEO do not.
The risk part is definitely true. As with any Black Hat SEO method, there may be benefits in the short term, but as your methods age they will likely get picked up by new search engine algorithm updates. For example, take hidden text. Many webmasters years ago would make text the same color as the background of a page in order to stuff the page's content with repetitions of popular keywords, hoping to get a high ranking. Occassionally I will come across a site that's still using this method, but over time, the search engines weed these bad folks out.
But fear not. For those who want to throw some money at a web site and have it ranked well (and quickly), take the PPC route. Pay-per-click advertising reaches just as many people if not more (with Google content ads) than organic search engine listings. Hire a capable PPC campaign manager and you will probably see a good return on your monthly budget. Google AdWords and Yahoo! Search Marketing are the most popular services for PPC advertising.
And if you still want to buy links, do what Google says and use the 'nofollow' tag. Set up a link for direct click-throughs from potential customers, not to increase your link popularity.