Mckinseyquarterly.com is converting to a paid site this summer: "Don't miss out on 100% unrestricted access to mckinseyquarterly.com, including first look at new articles and comprehensive archive searching [...] Free access will soon be limited to 10% of the site's content."

The price is $150 a year, which includes access to 10 years of archives. Thanks to Martin Röll for the tip.