What has your success been with link building?

Selected answers from the Dumb SEO Questions Facebook & G+ community.

• 
  Michael Martinez: As a general rule I assume that the more difficult it is to get someone to link to your site the more likely they only want to link to sites that they believe their visitors would genuinely be interested in and need to know about in connection with their own content.
  
  As a stingy linker (this expression is actually used by some search engineers in their research papers), I tend to link out to sites that:
  
  1) Provide original research
  2) Publish first-hand experience anecdotes
  3) Explain concepts extremely well (far better than the average "please link to my post" blogger)
  4) Have authors who demonstrate to me they really understand what they are talking about (listing educational credits on an "about" page doesn`t do that for me)
  5) Have clear and specific purposes (not using "link bait" or "pagerank traps" unrelated to the main site`s content)
  
  I rarely, rarely accept link requests. I find the sites I choose to link to in Web search. I specifically go looking for good link destinations when I am writing articles I feel should link out to something helpful.
  
  So being expert, helpful, and easy to find in search tends to work best for someone like me.
  
  And when I look at the natural backlink profiles for the sites in our portfolios, the sites that earn the most links meet that criteria (in my obviously biased opinion).