I mentioned my thoughts on this yesterday in this post. I think it deserves some discussion so am posting a separate thread about it. Like I said in that post, I think competition for specific keywords and phrases may play a role in Supplemental Results. I've noticed on some of my sites that those in very highly competitive niches get thrown into Supplemental Index quite easily if you do not have any, or many, external deep links to those pages. While with very low competition niches, pages can remain in main index with no external deep links to the pages. Am I out to lunch on this, or has anyone else noticed this. Original Content is a given here.