The most common way for people to find products or services online is to use search engines, especially Google, Bing or Yahoo. These search engines have certain criteria for giving websites more (or less) opportunity to be returned in search results. The way to obtain dependable, long term search engine optimization is to post as much quality content to your website as possible. The more unique readable text your site contains, the more logical area search engines will have to index and thus refer people to your site. More quality content means more opportunities for your website or blog to receive traffic from major search engines.
I've ranked websites in the past with spun content, and now they are still on #1 position of google. First year (2014) google found me because my spun was really bad, many paragraphs were just copied and my position drop from #2 to around #20 after a panda update. Later I cleaned all my text with better spun (I didn't buy any article!), my ranking went up again, and with more backlinks I reached #1 and it is still there