From the NY Times:

The New York Times Company announced this afternoon that it had agreed to acquire the online consumer information provider About Inc. from Primedia Inc., a magazine publisher, for $410 million in cash.

The acquisition is the biggest for the Times Company since it acquired The Boston Globe for $1.1 billion in 1993.
Times Company to Buy About.com for $410 Million [NYT]
New York Times Acquires About.com [AdAge]