SpinnerChief is designed to generate unique articles to provide content for websites and increase site traffic. It does this by spinning one article into multiple versions of itself, replacing certain words, phrases, and sentences with alternate versions of themselves. SpinnerChief can identify parts of speech, correct grammar errors, and use intelligent auto-replace methods until the article is both human-readable and passes Copyscape (a plagiarism checker). The SpinnerChief API allows developers to access SpinnerChief's functions from within other programs and can spin articles in 27 different languages.
Quality readable content is key here. Google, for example, will recognize that people are leaving your site soon after arriving if they perceive that your site or blog is full of junk content. This is called "bounce rate." If your bounce rate is high, then people are quickly leaving your site. But for the sake of your business, to build your online reputation and brand, you want people to visit your site, stay for a while, and then keep revisiting over the long term.
Imo it is not possible for google to detect properly spun content, it is not worth computing power it requires. They can do this using ngrams for example, but it is uses a lot of queries. And for example article spinner I coded beats this algo, so google cant detect that the content is spun. Manual spinning is also good but it takes more than 30 minutes per article.