I've been getting some really good exclusive content for one of my sites recently, and this has acted as linkbait for some pretty major sites - I've got a backlink from yahoo.com and a number of other PR6-7 domains. Would it prove beneficial for me to build backlinks to these articles, and does anyone have any idea how many links I should build to domains of this size? I was planning to write my own hand-spun article to ensure unique but readable content, building 50 web 2.0 links, 10 PR0-1 links and 5 PR2-3 links to each article with a blast of social bookmarks to all links - does this sound like a good plan? The last thing I want to do is ruin the authority I have gained as a result of these links - there has been a noticeable ranking improvement since I got them - so I'm not averse to just leaving them alone. The article will be super-spun at paragraph, sentence, phrase & word level so I'm not worried about duplicate content - and I am aware I will need to vary the anchor text - but I'd like to know if there's anything else I should look out for should I opt to build a 2nd/3rd tier.