Just got kicked completey out of google for a highly competitive keyword. Dont make this mistake I did. As long as you are in a niche you are likely under the radar. But as soon as you compete head on for a major keyword your sight will be looked at with a fine tooth comb, but not by google. By your competitors. Then they will report you to google. I was using Auto Blog Samuri and posting Youtube videos combine with spun copy(not very readable), and a jpg fro my pc. .It was a mix of youtube scrape and some semi original content . Also a ton of spammy links from comments, twitter clones, etc. Not a problem with googlebot it doesnt know the difference. But in a high competitve situation you will get reported even if you think your legit. Doesnt matter. Expect it. Bottom line is if you are ranking for a major keyword for long term be sure and do EVERYTHING above board because there will be many well trained eyes looking at. I will start over but I may hire copywriters this time.