Since it evolved into a news site in 2006, NYmag.com has been building a sizable national audience.  Fashion has been a big traffic driver and Fashion Week in New York and brought historic traffic to the site, according to a report in Mediabistro’s WebNewser. Last month, I interviewed New York magazine's Web chief Michael Silberman on the evolution of the site. He says the blog strategy has been extremely effective. — Andy Plesser, Executive Producer