I have been looking at a few very competitive niches to understand how they are ranking for terms like weight loss, slimming pills, viagra, etc as it is good to get some ideas, even if they are way beyond black hat and not my industry. So, I saw a site that was ranking at no.2 for a Viagra keyphrase - think it was Viagra Coupons or something similar and had a quick look at some of its backlinks in Majestic. I didn't check but they must get millions of searches for phrases like that. A couple of the domains it is pointing to, with exact match anchor text, are for mainstream sites like football, a family centre and a restaurant. There is no link on the pages as you look at them but their link is in the source code as I described. How do they do this? Do they own the sites in question? Have they 'injected' their link without the site owners knowledge? It is obviously more than white on white text as the link doesn't appear on the pages even if you hover over them. I know nothing about this type of thing but I'm curious. Can anyone shed any light on this?