It's a long, long job to research your keywords, keyword phrases, LSi's etc and then to write content for your chosen search term that has the perfect keywords, and the perfect density of those keywords. This plugin looks at the top 10 Google SERPS for your search term, compares them to each other, and then tells you the keywords that ALL the top 10 pages are using in their content, PLUS the density of those keywords. In less than a minute you will know EXACTLY which keywords and their relevant density to include in your website copy so that it matches Google's exact keyword expectations. Click here for more details.
Spin Rewriter 9.0 allows their users to have hundreds of articles of similar high quality in a short amount of time. They have updated the ENL Semantic Spinning engine to include synonyms and sentence structure variants. Their article software that is spinning is of the best in the market and they have kept their costs affordable. Website professionals are using spin Rewriter. High profile customers have stated; the Rewriter tool is used with a marketing budget as a savings model for any business.
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.