indyank - 4:13 pm on Aug 17, 2012 (gmt 0)

Wikipedia's outbound links to references open in the same window.

For wikipedia, considering the huge number of internal links which tend to dwarf the relatively very small number of external links and the fact that external links are way below the fold on most of their pages would translate to almost no clicks on them.

However, I have never seen any difference between opening external links in the same window and in a newer window.