Answers.com has no bother with trying to edit content for quality, like Wikipedia does, either. They just have all the content, at no cost. The profits they make, they use to advertise on Google AdSense. All of this just gives the bloggers great ideas about how they just have to pump out nonsense on a massive scale , advertise a bit, and there you have your instant millionaire formula. Demand Media actually pays freelancers for this too.

Google is the reason why these websites choose their path of mas content-isation – Google’s policy of how the most new additions to a website makes it the most popular. It is quickly becoming so that any standard search for information on a topic gives you nothing but a results page that is clogged with banalities from Answers.com, WikiAnswers and Yahoo Answers. This is also what happens with any standard newspaper that has grown fat and old on its own success. How could this be what the Internet has turned into? How will people find articles from genuine freelancing experts who aren’t on the payroll of a major magazine?

Most of them know that Google ranks websites under organic and inorganic search ranking. Do you know how it categorizes them? It is simple, if a website is well optimized using SEO techniques like press release, article submission, directories submission, forum, blog etc without using paid links, then Google will place the website under the organic search ranking. If a website is promoted mostly through the paid links, then the corresponding website will be listed under the inorganic search ranking.

Websites covered under the Organic and Inorganic search rankings are displayed at the left and right sides of the Search Engine Result Page (SERP), respectively. Most often, users trust a website, if it is listed in the organic listing.

With this explanation, you may conclude that the paid link is fruitless. But this is not true; Google will accept the links purchased for advertising purpose and it is purely against the links that are purchased for the purpose of getting high PR and that are part of the planned link exchange program.

Obviously, you can use Google Adsense for advertising purposes, and gain top ranking. Not only Google, you can also buy text advertisements from someone else to achieve better results in search engines.
Apart from the paid links, you can also build links by exchanging links with sites offering useful information for your site visitors. If your site has enough useful information, then other similar sites will be ready to place your site link without link exchange.

To put it in the nut shell, getting the paid links for advertising purpose will drive targeted traffic and help you achieve high PR.