There is a large debate in the SEO world about whether or not Google is using themes to determine ranking. Does it matter if the backlinks you receive to your site are on-theme or not? Do they all count, regardless of theme? And if they do all count, are on-theme backlinks given a greater score than off-theme links? And what about site content? If your entire site revolves around a central theme, does this help with ranking for that theme? And if so, is it only the internal links that clues Google in to the theme, or do on-page properties help as well? All good questions...I'll be revisiting this topic later.