I'm building a small social Q&A site. Another Q&A site that I use was recently branded by Google as a content farm and removed from Google results. I know what Wikipedia says is the definition of a content farm (low quality paid articles and spammy text across the page to catch search engines). That other site I use doesn't do those things, so there must be more to it than that. I want to make sure I don't do anything that causes Google to think my Q&A site is a content farm. What should I do, or avoid doing in designing my site layout?